(PUP-2010) have test repos pushed to hosts during acceptance testing

This patch changes the logic of how test packages are installed on SUTs.
Currently, repo packages are pulled by the individual SUTs - this works
because we assume that the SUTs are located within the Puppet Labs
network and can access builds.puppetlabs.lan. To run acceptance tests
in the cloud the workflow needs to be changed to have the test packages
pushed to the SUTs by the jenkins master node.

Tested successfully on jenkins, also updated spec tests.

This code relies on Beaker 1.8+ DSL methods.
(maint) Fix two spec tests to be robust when running in a path with parens

Both of these spec tests were including the working directory (via
the 'envdir' variable) in the regex to match against, but did so without
properly escaping the directory path. This meant that if the working
directory path included parentheses they were interpreted as regex
symbols rather than bare parentheses.

This could be fixed by wrapping the envdir in Regexp.escape, but
the path isn't really important to check for in this warning message,
so I just removed it from the regex.
Merge pull request #2456 from anodelman/stable

(PUP-2010) have test repos pushed to hosts during acceptance testing