implementing overrideable puppet and librarian versions
adding docs for puppet and loom versions if they are None
Merge pull request #25 from sherzberg/custom_puppet_versions

Custom puppet and librarian versions
adding helper to check if librarian is installed
if librarian not installed, abort
Merge pull request #27 from sherzberg/haslibrarian

Helper methods to check for installation of Librarian
adding a requires_puppet decorator to abstract out error messages
better assert for the correct abort text
Merge pull request #28 from sherzberg/requirespuppetdecorator

Added requires_puppet task decorator and tests
gitignore
Upgrade fabric
Travis CI
s/before-script/before_script/
Renamed dev-requirements.txt because of autocomplete
Travis badge in readme
merging upstream/master