Set rspec-core < 3.0.0 in Gemfile
Set rspec-core < 3.0.0 in Gemfile

Due to the issue in PUP-3594, there are rspec deprecation warning thrown
during runs of the automated tests.

This commit explicitly forces the rspec version to be less than 3.0.0 in
order to mitigate the issue as per PUP-3594.

DavidS/puppetlabs-tagmail,puppetlabs/puppetlabs-tagmail,jonnytpuppet/puppetlabs-tagmail