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/callback_type.go b/vendor/github.com/opencord/voltha-go/db/model/callback_type.go
new file mode 100644
index 0000000..b530dee
--- /dev/null
+++ b/vendor/github.com/opencord/voltha-go/db/model/callback_type.go
@@ -0,0 +1,47 @@
+/*
+ * 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
+
+// CallbackType is an enumerated value to express when a callback should be executed
+type CallbackType uint8
+
+// Enumerated list of callback types
+const (
+	GET CallbackType = iota
+	PRE_UPDATE
+	POST_UPDATE
+	PRE_ADD
+	POST_ADD
+	PRE_REMOVE
+	POST_REMOVE
+	POST_LISTCHANGE
+)
+
+var enumCallbackTypes = []string{
+	"GET",
+	"PRE_UPDATE",
+	"POST_UPDATE",
+	"PRE_ADD",
+	"POST_ADD",
+	"PRE_REMOVE",
+	"POST_REMOVE",
+	"POST_LISTCHANGE",
+}
+
+func (t CallbackType) String() string {
+	return enumCallbackTypes[t]
+}