Add spec tests and some minor cleanup

[adamcrews]

This is a rather large PR that adds unit testing and does some minor cleanup.
The highlights are:

• Functionally identical to the main master branch.
• Switches to the newer metadata.yaml instead of the old Modulefile for forge info.
• Adds unit tests
• Adds travis.yaml for travis ci testing (a build of this commit can be seen at https://travis-ci.org/adamcrews/Loggly-Puppet/builds/59674347)
• Adds class parameter validation
• removes util::line in favor of puppet/stdlib file_line
• compatibility checks for Puppet 4 and the future parser
• bumps

This PR obsoletes #9

I am running this version in my production environment without issue.

[mostlyjason]

Thanks Adam! Unfortunately, our Puppet expert isn't available so we'll have to trust your tests. I still think it's good to release what you have. We'll just have to keep an eye on anything that pops up.