Use official python bindings in Librato's handler.
Don't run userscript test if kitchen isn't avail

This mimics other tests where part of the resources aren't available.
Merge pull request #267 from drio/master

Use official python bindings in Librato's handler.
Test for kitchen only when necessary
Merge pull request #266 from j2sol/master

Don't run userscript test if kitchen isn't avail
Doc updates