Remove logstash_commons dependency

Migrated the `logstash_commons` calls to use attributes on elkstack instead. Added tests to verify the templates are pushed out successfully when converged with elkstack::agent in a wrapper recipe. If elkstack isn't present, these additional attributes simply do nothing. If elkstack is present but a particular technology is not present, logstash simply ignores log files it doesn't find.
version dump after merge with upstream, since the upstream version was the same bump as mine
Merge pull request #25 from martinb3/master

Remove logstash_commons dependency