Migrate bundler based jobs to ruby2.0 (on Trusty)

Change the bundle jobs to use ruby2.0 which is installed by puppet
change: https://gerrit.wikimedia.org/r/#/c/166046/

gem2.0 deprecated `--no-ri --no-doc` in favor of `--no-document`

Change-Id: Ia3958f4201e72f5669a00caf9195d95c0662d77c