1. Added C++ tests under the release docker image.
2. Cleaned up tests.sh and removed traivis stuff.

1. Added C++ tests under the release docker image.
2. Fixed a compile issue with the docker image.
3. Cleaned up tests.sh and removed traivis stuff.

Add googletest as a submodule in third_party/googletest.

The last up-integration from github to google3 was made at commit
e28286fa but somehow the change in
that commit is not actually in the up-integration CL and as a result
that change was reverted by the down-integration. Restoring them
should make the jenkins tests running again.

When it runs in parallel with other jenkins tests, multiple tests start
to fail probably because cpp_distcheck will update the C++ lib that
other tests (such as python_cpp) are depending on.

Change-Id: Ibca0243084bb6b81c811b62c75288e20cc2aabf5

These tests are already covered by jenkins and right now jenkins can
finish these tests much quicker then travis.

Change-Id: I5799761ccc338211d750940e3cf4c8e2569c8144

1. Added ruby22 and jruby tests to jenkins.
2. Added javascript tests to jenkins.
3. Added golang tests to jenkins.
4. Removed ruby19/ruby20 tests from travis. Support for ruby 2.0 has
   ended since 2016/02/24.
   https://www.ruby-lang.org/en/news/2016/02/24/support-plan-of-ruby-2-0-0-and-2-1/

Change-Id: Ie984b06772335352a4be7067ab2485f923875685