Extend apiserver testserver such that in can be used in integration tests

abstract out etcd server creation
test/integration/framework: cleanup master_utils.go
kube-apiserver: move StartTestServer tests into test/integration/master
Fix the failing scale test
kube-apiserver's TestServer now returns a struct instead of individual values

test/integration/garbagecollector/main_test.go

@@ -0,0 +1,27 @@
+/*
+Copyright 2017 The Kubernetes Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package garbagecollector
+
+import (
+	"testing"
+
+	"k8s.io/kubernetes/test/integration/framework"
+)
+
+func TestMain(m *testing.M) {
+	framework.EtcdMain(m.Run)
+}