Refactored gemspec to use Bundler boilerplate patterns
Added functional tests, added --puppetfile option

They use the Puppetfile in spec/fixtures and create temporary
directories to run the tests. The file is specified using the
new --puppetfile option, which doesn't exist on librarian-pupppet,
but is optional, by default it will use ./Puppetfile

Right now they use modules hosted on both github and forge,
if these services are offline the tests will fail, but this is
better than nothing.
Fixed small mistake on untar procedure, will add tests later
Merge pull request #3 from rafaelrosafu/master

Added specs and --puppetfile option