(maint) Remove RC (Release Candidate) references

With the introduction of nightlies.puppetlabs.com, we are dropping
RCs as part of the release process. So remove references in the
release tickets.
(CPR-63) Template mock configs

This commit adds in capabilities that check if a template for mock
configs are in place then creates the mock config from them. It then
uses the newly made mock configs in the usual method. This is intended
to be used instead of needing a new config generated for every pe
version.
It will also be helpful for building for a pe version that hasn't had
mock configs generated yet.
(CPR-63) Add requiring pe version

This commit adds the requirement that pe version be given by environment
variable so the mock configs can be generated correctly.
Fix mock config directories

This commit fixes the mock config directories and adds a variable for the mock name
so that things are correctly instantiated.