Merge branch 'stable-3.1'

* stable-3.1:
  Upgrade bazlets to latest stable-3.1 to build with 3.1.4 API
  Upgrade bazlets to latest stable-2.16 to build with 2.16.17 API
  Upgrade bazlets to latest stable-3.0 to build with 3.0.8 API
  Upgrade bazlets to latest stable-3.1

Change-Id: If3619ba18be313faabda6de45ab14146271bc065

WORKSPACE

diff --git a/WORKSPACE b/WORKSPACE
index e111345..a61c92a 100644
--- a/WORKSPACE
+++ b/WORKSPACE
@@ -3,7 +3,7 @@
 load("//:bazlets.bzl", "load_bazlets")
 
 load_bazlets(
-    commit = "fc1bfdf008c4b07e7cc4214fdacf25560276f9c4",
+    commit = "2add9fecf8bec8634bddf354815bd0fa93f58dd5",
     #local_path = "/home/<user>/projects/bazlets",
 )