bin/test for Active Job and Action Cable tests

According to the commit comment on 54d84cbb77, AJ/bin/test was intentionally not added,
but AJ tests doesn't actually do anything special other than specifying ENV['AJ_ADAPTER'],
which can be easily done via command line environment variable.

actioncable/bin/test

@@ -0,0 +1,4 @@
+#!/usr/bin/env ruby
+
+COMPONENT_ROOT = File.expand_path("..", __dir__)
+require File.expand_path("../tools/test", COMPONENT_ROOT)

activejob/bin/test

@@ -0,0 +1,4 @@
+#!/usr/bin/env ruby
+
+COMPONENT_ROOT = File.expand_path("..", __dir__)
+require File.expand_path("../tools/test", COMPONENT_ROOT)