Extend presubmit to covert test and request (#1846)

Fix the casing *and* fix use of context as we were still referencing
the non-std lib context - no wondering how this could have worked...

test/etcd_test.go

@@ -3,6 +3,7 @@
 package test
 
 import (
+	"context"
 	"encoding/json"
 	"io/ioutil"
 	"log"
@@ -17,7 +18,6 @@ import (
 
 	etcdc "github.com/coreos/etcd/client"
 	"github.com/miekg/dns"
-	"golang.org/x/net/context"
 )
 
 func etcdPlugin() *etcd.Etcd {