WORKSPACE: add bazel docker rules
diff --git a/WORKSPACE b/WORKSPACE
index 5f65be1..29baa39 100644
--- a/WORKSPACE
+++ b/WORKSPACE
@@ -1,7 +1,8 @@
-# Python rules
-
 load("@bazel_tools//tools/build_defs/repo:git.bzl", "git_repository")
+load("@bazel_tools//tools/build_defs/repo:http.bzl", "http_archive")
 
+
+# Python rules
 git_repository(
     name = "io_bazel_rules_python",
     remote = "https://github.com/bazelbuild/rules_python.git",
@@ -21,9 +22,16 @@
 
 pip_install()
 
-# Go rules
+# Docker rules
 
-load("@bazel_tools//tools/build_defs/repo:http.bzl", "http_archive")
+http_archive(
+    name = "io_bazel_rules_docker",
+    sha256 = "aed1c249d4ec8f703edddf35cbe9dfaca0b5f5ea6e4cd9e83e99f3b0d1136c3d",
+    strip_prefix = "rules_docker-0.7.0",
+    urls = ["https://github.com/bazelbuild/rules_docker/archive/v0.7.0.tar.gz"],
+)
+
+# Go rules
 
 http_archive(
     name = "io_bazel_rules_go",