(doc) Add comment on how to enable remote puppet agents
Installing Puppet Server from packages quick start docs
(PE-6073) Fix rake spec tests

This commit changes the expected version in the puppet version spec test
to 3.7.1 so that the test is sync with current puppet submodule being
selected by the project.

This commit also wraps the `RSpec::Core::Runner.run` call that
run_specs.rb makes in an exit call so that the return code from the
`run` call is propagated out.  Previously, the result from the `run`
call was swallowed, causing the calling application to always have an
exit code of 0 even if tests had failed.
Update README.md
Merge pull request #189 from nwolfe/installing-from-packages-quick-start

Installing Puppet Server from packages quick start docs
(DOCS) Add Known Issues section to README
Merge pull request #191 from nwolfe/readme-known-issues

(DOCS) Add Known Issues section to README
Merge pull request #190 from camlow325/maint/master/PE-6073-fix-rake-spec-tests

(PE-6073) Fix rspec tests
Merge pull request #188 from kylog/doc/add-comment-re-remote-puppet-agents

(doc) Add comment on how to enable remote puppet agents