go/svc/invoice: statusz cleanups

 - Remove internal ID
 - Sort by time
diff --git a/go/svc/invoice/statusz.go b/go/svc/invoice/statusz.go
index f076299..525d61e 100644
--- a/go/svc/invoice/statusz.go
+++ b/go/svc/invoice/statusz.go
@@ -4,6 +4,8 @@
 	"context"
 	"fmt"
 	"net/http"
+	"sort"
+	"time"
 
 	"code.hackerspace.pl/hscloud/go/mirko"
 	"code.hackerspace.pl/hscloud/go/statusz"
@@ -31,8 +33,8 @@
 		{{ .Msg }}
         <table class="table">
             <tr>
-                <th>Internal ID</th>
                 <th>Number</th>
+				<th>Created/Issued</th>
 				<th>Customer</th>
 				<th>Amount (net)</th>
 				<th>Actions</th>
@@ -43,8 +45,8 @@
 				{{ else }}
 				<tr style="opacity: 0.5">
 				{{ end }}
-				    <td>{{ .Uid }}</td>
 				    <td>{{ .FinalUid }}</td>
+					<td>{{ .DatePretty.Format "2006/01/02 15:04:05" }}</td>
 					<td>{{ index .Data.CustomerBilling 0 }}</td>
 					<td>{{ .TotalNetPretty }}</td>
 				    <td>
@@ -59,6 +61,7 @@
 type templateInvoice struct {
 	*pb.Invoice
 	TotalNetPretty string
+	DatePretty     time.Time
 }
 
 func (s *service) setupStatusz(m *mirko.Mirko) {
@@ -73,6 +76,7 @@
 			res.Invoices[i] = templateInvoice{
 				Invoice:        inv,
 				TotalNetPretty: fmt.Sprintf("%.2f %s", float64(inv.TotalNet)/100, inv.Unit),
+				DatePretty:     time.Unix(0, inv.Date),
 			}
 		}
 
@@ -80,6 +84,8 @@
 			glog.Errorf("Could not get invoices for statusz: %v", err)
 			res.Msg = fmt.Sprintf("Could not get invoices: %v", err)
 		}
+
+		sort.Slice(res.Invoices, func(i, j int) bool { return res.Invoices[i].Date > res.Invoices[j].Date })
 		return res
 	})