Remove spurious bundle install from .travis.yml
Remove spurious bundle install from .travis.yml

Travis handles the bundle install from the top-level Gemfile for us, so
it's unnecessary to repeat it here.

alphagov/paas-cf,alphagov/paas-cf,alphagov/paas-cf,alphagov/paas-cf,alphagov/paas-cf,alphagov/paas-cf,alphagov/paas-cf,alphagov/paas-cf