diff --git a/go/vendor/github.com/asaskevich/govalidator/utils.go b/go/vendor/github.com/asaskevich/govalidator/utils.go
new file mode 100644
index 0000000..6a8871c
--- /dev/null
+++ b/go/vendor/github.com/asaskevich/govalidator/utils.go
@@ -0,0 +1,264 @@
+package govalidator
+
+import (
+	"errors"
+	"fmt"
+	"html"
+	"math"
+	"path"
+	"regexp"
+	"strings"
+	"unicode"
+	"unicode/utf8"
+)
+
+// Contains check if the string contains the substring.
+func Contains(str, substring string) bool {
+	return strings.Contains(str, substring)
+}
+
+// Matches check if string matches the pattern (pattern is regular expression)
+// In case of error return false
+func Matches(str, pattern string) bool {
+	match, _ := regexp.MatchString(pattern, str)
+	return match
+}
+
+// LeftTrim trim characters from the left-side of the input.
+// If second argument is empty, it's will be remove leading spaces.
+func LeftTrim(str, chars string) string {
+	if chars == "" {
+		return strings.TrimLeftFunc(str, unicode.IsSpace)
+	}
+	r, _ := regexp.Compile("^[" + chars + "]+")
+	return r.ReplaceAllString(str, "")
+}
+
+// RightTrim trim characters from the right-side of the input.
+// If second argument is empty, it's will be remove spaces.
+func RightTrim(str, chars string) string {
+	if chars == "" {
+		return strings.TrimRightFunc(str, unicode.IsSpace)
+	}
+	r, _ := regexp.Compile("[" + chars + "]+$")
+	return r.ReplaceAllString(str, "")
+}
+
+// Trim trim characters from both sides of the input.
+// If second argument is empty, it's will be remove spaces.
+func Trim(str, chars string) string {
+	return LeftTrim(RightTrim(str, chars), chars)
+}
+
+// WhiteList remove characters that do not appear in the whitelist.
+func WhiteList(str, chars string) string {
+	pattern := "[^" + chars + "]+"
+	r, _ := regexp.Compile(pattern)
+	return r.ReplaceAllString(str, "")
+}
+
+// BlackList remove characters that appear in the blacklist.
+func BlackList(str, chars string) string {
+	pattern := "[" + chars + "]+"
+	r, _ := regexp.Compile(pattern)
+	return r.ReplaceAllString(str, "")
+}
+
+// StripLow remove characters with a numerical value < 32 and 127, mostly control characters.
+// If keep_new_lines is true, newline characters are preserved (\n and \r, hex 0xA and 0xD).
+func StripLow(str string, keepNewLines bool) string {
+	chars := ""
+	if keepNewLines {
+		chars = "\x00-\x09\x0B\x0C\x0E-\x1F\x7F"
+	} else {
+		chars = "\x00-\x1F\x7F"
+	}
+	return BlackList(str, chars)
+}
+
+// ReplacePattern replace regular expression pattern in string
+func ReplacePattern(str, pattern, replace string) string {
+	r, _ := regexp.Compile(pattern)
+	return r.ReplaceAllString(str, replace)
+}
+
+// Escape replace <, >, & and " with HTML entities.
+var Escape = html.EscapeString
+
+func addSegment(inrune, segment []rune) []rune {
+	if len(segment) == 0 {
+		return inrune
+	}
+	if len(inrune) != 0 {
+		inrune = append(inrune, '_')
+	}
+	inrune = append(inrune, segment...)
+	return inrune
+}
+
+// UnderscoreToCamelCase converts from underscore separated form to camel case form.
+// Ex.: my_func => MyFunc
+func UnderscoreToCamelCase(s string) string {
+	return strings.Replace(strings.Title(strings.Replace(strings.ToLower(s), "_", " ", -1)), " ", "", -1)
+}
+
+// CamelCaseToUnderscore converts from camel case form to underscore separated form.
+// Ex.: MyFunc => my_func
+func CamelCaseToUnderscore(str string) string {
+	var output []rune
+	var segment []rune
+	for _, r := range str {
+
+		// not treat number as separate segment
+		if !unicode.IsLower(r) && string(r) != "_" && !unicode.IsNumber(r) {
+			output = addSegment(output, segment)
+			segment = nil
+		}
+		segment = append(segment, unicode.ToLower(r))
+	}
+	output = addSegment(output, segment)
+	return string(output)
+}
+
+// Reverse return reversed string
+func Reverse(s string) string {
+	r := []rune(s)
+	for i, j := 0, len(r)-1; i < j; i, j = i+1, j-1 {
+		r[i], r[j] = r[j], r[i]
+	}
+	return string(r)
+}
+
+// GetLines split string by "\n" and return array of lines
+func GetLines(s string) []string {
+	return strings.Split(s, "\n")
+}
+
+// GetLine return specified line of multiline string
+func GetLine(s string, index int) (string, error) {
+	lines := GetLines(s)
+	if index < 0 || index >= len(lines) {
+		return "", errors.New("line index out of bounds")
+	}
+	return lines[index], nil
+}
+
+// RemoveTags remove all tags from HTML string
+func RemoveTags(s string) string {
+	return ReplacePattern(s, "<[^>]*>", "")
+}
+
+// SafeFileName return safe string that can be used in file names
+func SafeFileName(str string) string {
+	name := strings.ToLower(str)
+	name = path.Clean(path.Base(name))
+	name = strings.Trim(name, " ")
+	separators, err := regexp.Compile(`[ &_=+:]`)
+	if err == nil {
+		name = separators.ReplaceAllString(name, "-")
+	}
+	legal, err := regexp.Compile(`[^[:alnum:]-.]`)
+	if err == nil {
+		name = legal.ReplaceAllString(name, "")
+	}
+	for strings.Contains(name, "--") {
+		name = strings.Replace(name, "--", "-", -1)
+	}
+	return name
+}
+
+// NormalizeEmail canonicalize an email address.
+// The local part of the email address is lowercased for all domains; the hostname is always lowercased and
+// the local part of the email address is always lowercased for hosts that are known to be case-insensitive (currently only GMail).
+// Normalization follows special rules for known providers: currently, GMail addresses have dots removed in the local part and
+// are stripped of tags (e.g. some.one+tag@gmail.com becomes someone@gmail.com) and all @googlemail.com addresses are
+// normalized to @gmail.com.
+func NormalizeEmail(str string) (string, error) {
+	if !IsEmail(str) {
+		return "", fmt.Errorf("%s is not an email", str)
+	}
+	parts := strings.Split(str, "@")
+	parts[0] = strings.ToLower(parts[0])
+	parts[1] = strings.ToLower(parts[1])
+	if parts[1] == "gmail.com" || parts[1] == "googlemail.com" {
+		parts[1] = "gmail.com"
+		parts[0] = strings.Split(ReplacePattern(parts[0], `\.`, ""), "+")[0]
+	}
+	return strings.Join(parts, "@"), nil
+}
+
+// Truncate a string to the closest length without breaking words.
+func Truncate(str string, length int, ending string) string {
+	var aftstr, befstr string
+	if len(str) > length {
+		words := strings.Fields(str)
+		before, present := 0, 0
+		for i := range words {
+			befstr = aftstr
+			before = present
+			aftstr = aftstr + words[i] + " "
+			present = len(aftstr)
+			if present > length && i != 0 {
+				if (length - before) < (present - length) {
+					return Trim(befstr, " /\\.,\"'#!?&@+-") + ending
+				}
+				return Trim(aftstr, " /\\.,\"'#!?&@+-") + ending
+			}
+		}
+	}
+
+	return str
+}
+
+// PadLeft pad left side of string if size of string is less then indicated pad length
+func PadLeft(str string, padStr string, padLen int) string {
+	return buildPadStr(str, padStr, padLen, true, false)
+}
+
+// PadRight pad right side of string if size of string is less then indicated pad length
+func PadRight(str string, padStr string, padLen int) string {
+	return buildPadStr(str, padStr, padLen, false, true)
+}
+
+// PadBoth pad sides of string if size of string is less then indicated pad length
+func PadBoth(str string, padStr string, padLen int) string {
+	return buildPadStr(str, padStr, padLen, true, true)
+}
+
+// PadString either left, right or both sides, not the padding string can be unicode and more then one
+// character
+func buildPadStr(str string, padStr string, padLen int, padLeft bool, padRight bool) string {
+
+	// When padded length is less then the current string size
+	if padLen < utf8.RuneCountInString(str) {
+		return str
+	}
+
+	padLen -= utf8.RuneCountInString(str)
+
+	targetLen := padLen
+
+	targetLenLeft := targetLen
+	targetLenRight := targetLen
+	if padLeft && padRight {
+		targetLenLeft = padLen / 2
+		targetLenRight = padLen - targetLenLeft
+	}
+
+	strToRepeatLen := utf8.RuneCountInString(padStr)
+
+	repeatTimes := int(math.Ceil(float64(targetLen) / float64(strToRepeatLen)))
+	repeatedString := strings.Repeat(padStr, repeatTimes)
+
+	leftSide := ""
+	if padLeft {
+		leftSide = repeatedString[0:targetLenLeft]
+	}
+
+	rightSide := ""
+	if padRight {
+		rightSide = repeatedString[0:targetLenRight]
+	}
+
+	return leftSide + str + rightSide
+}