Invoke Rubocop and TravisLint checks in bundle context
Invoke Rubocop and TravisLint checks in bundle context

Now that we're on Overcommit 0.22.0, we can invoke these commands in a
Bundler context to ensure the version of the tool specified by the
Gemfile.lock is run.

Change-Id: Iba4c0b551e03ae164cead17b3fcb361f2809ba1f
Reviewed-on: http://gerrit.causes.com/46523
Tested-by: jenkins <d95b56ce41a2e1ac4cecdd398defd7414407cc08@brigade.com>
Reviewed-by: Shane da Silva <67fb7bfe39f841b16a1f86d3928acc568d12c716@brigade.com>

skateman/haml-lint,mzp/haml-lint