VOL-1497 : Add more control to kv/memory access

- Added kv locking mechanism (etcd only)
- (watch) control path access whenever possible
- (watch) use a transaction for updates and merge with memory
- cleaned up vendoring
- misc changes to fix exceptions found along the way

Amendments:

- Copyright header got removed in auto-generated file
- Changed default locking to false for KV list operation
- Updated backend api to allow the passing of locking parameter

Change-Id: Ie1a55d3ca8b9d92ae71a85ce42bb22fcf1419e2c
diff --git a/vendor/github.com/hashicorp/go-immutable-radix/.travis.yml b/vendor/github.com/hashicorp/go-immutable-radix/.travis.yml
new file mode 100644
index 0000000..1a0bbea
--- /dev/null
+++ b/vendor/github.com/hashicorp/go-immutable-radix/.travis.yml
@@ -0,0 +1,3 @@
+language: go
+go:
+  - tip