Upgrade Rubocop to 0.29.0 for Travis builds
Upgrade Rubocop to 0.29.0 for Travis builds

Change-Id: I7968a51459b43395ef38cc7c6bce160d6cd0a143
Reviewed-on: http://gerrit.causes.com/46310
Tested-by: jenkins <d95b56ce41a2e1ac4cecdd398defd7414407cc08@brigade.com>
Reviewed-by: Shane da Silva <67fb7bfe39f841b16a1f86d3928acc568d12c716@brigade.com>

skateman/haml-lint,mzp/haml-lint