VOL-1558 Update vendored voltha-go and other items

Result of running dep ensure.  golang openolt now
builds.

Also update dockerfile to used specific alpine version

Change-Id: I1e5407e25bb0636a241a0650d1e44e5df567f44b
diff --git a/vendor/github.com/opencord/voltha-go/db/model/event_bus_client.go b/vendor/github.com/opencord/voltha-go/db/model/event_bus_client.go
new file mode 100644
index 0000000..c9c1314
--- /dev/null
+++ b/vendor/github.com/opencord/voltha-go/db/model/event_bus_client.go
@@ -0,0 +1,36 @@
+/*
+ * Copyright 2018-present Open Networking Foundation
+
+ * 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 model
+
+import (
+	"github.com/opencord/voltha-go/common/log"
+	"github.com/opencord/voltha-protos/go/voltha"
+)
+
+// EventBusClient is an abstraction layer structure to communicate with an event bus mechanism
+type EventBusClient struct {
+}
+
+// NewEventBusClient creates a new EventBusClient instance
+func NewEventBusClient() *EventBusClient {
+	return &EventBusClient{}
+}
+
+// Publish sends a event to the bus
+func (ebc *EventBusClient) Publish(topic string, event voltha.ConfigEvent) {
+	log.Debugf("publishing event:%+v, topic:%s\n", event, topic)
+}