pulp - updates to address issues in copy/associate of large repos

this commit contains small changes to address memory issues observed
when during the copy of large repos.

refer to https://bugzilla.redhat.com/show_bug.cgi?id=953665 for more
details
runcible - updating spec and bundler.d to use runcible 0.4.3
vcr_cassettes - regenerating cassettes
Merge pull request #2046 from bbuckingham/pulpv2-updates

pulp - updates for repo copy and retrieving packages