travis to work on newer versions and on multiplatforms

[or-shachar]

Previous travis ran only with bazel 0.3.2 and on linux.
This update makes sure travis will have 4 permutations:

• versions: latest (0.4.4) and head.
• platforms: linux and osx

#Notes:

• The source of this file is from go_rules adjusted to this repo
• I skipped all apt requirements but libxml2-utils that failed without it
• Those changes still don't solve issue test_run should be a sh_test #76 but will help test solutions to it
• I also added prints on duration of each test that is run by the test_run.sh

[bazel-io]

Can one of the admins verify this patch?

[johnynek]

This is great! Thanks for doing this!