pkg/services/sqlstore/user_auth_test.go: comment unused users slice

See,
$ gometalinter --vendor --deadline 10m --disable-all --enable=megacheck ./...
pkg/services/sqlstore/user_auth_test.go:28:18:warning: this result of append is never used, except maybe in other appends (SA4010) (megacheck)

pkg/services/sqlstore/user_auth_test.go

@@ -16,7 +16,6 @@ func TestUserAuth(t *testing.T) {
 	Convey("Given 5 users", t, func() {
 		var err error
 		var cmd *m.CreateUserCommand
-		users := []m.User{}
 		for i := 0; i < 5; i++ {
 			cmd = &m.CreateUserCommand{
 				Email: fmt.Sprint("user", i, "@test.com"),
@@ -25,7 +24,6 @@ func TestUserAuth(t *testing.T) {
 			}
 			err = CreateUser(context.Background(), cmd)
 			So(err, ShouldBeNil)
-			users = append(users, cmd.Result)
 		}
 
 		Reset(func() {