Merge branch 'stable-3.1'

* stable-3.1:
  Upgrade bazlets to latest stable-3.1 to build with 3.1.7 API
  Upgrade bazlets to latest stable-3.0 to build with 3.0.11 API
  Remove the commented-out snapshot plugin api lines
  Adapt SNAPSHOT plugin api example to the 3.1 version
  Upgrade bazlets to latest stable-3.1
  Prepare for new gerrit_api snapshot version usage
  Upgrade bazlets to latest stable-3.0
  Upgrade bazlets to latest stable-3.0

Change-Id: I7a68f953624851707187cbf9aafcfba6518a11be

WORKSPACE

diff --git a/WORKSPACE b/WORKSPACE
index 3d93f07..c554192 100644
--- a/WORKSPACE
+++ b/WORKSPACE
@@ -7,24 +7,13 @@
     #local_path = "/home/<user>/projects/bazlets",
 )
 
-# Release Plugin API
 load(
     "@com_googlesource_gerrit_bazlets//:gerrit_api.bzl",
     "gerrit_api",
 )
 
-# Snapshot Plugin API
-#load(
-#    "@com_googlesource_gerrit_bazlets//:gerrit_api_maven_local.bzl",
-#    "gerrit_api_maven_local",
-#)
-
-# Load release Plugin API
 gerrit_api()
 
 load("//:external_plugin_deps.bzl", "external_plugin_deps")
 
 external_plugin_deps()
-
-# Load snapshot Plugin API
-#gerrit_api_maven_local()