MM-33945: Update dependencies (#17201)

* MM-33945: Update dependencies

Ran `make update-dependencies`

https://mattermost.atlassian.net/browse/MM-33945

```release-notes
NONE
```

* fix test

vendor/github.com/google/btree/go.mod

@@ -0,0 +1,17 @@
+// Copyright 2014 Google Inc.
+//
+// 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.
+
+module github.com/google/btree
+
+go 1.12