Updated the README.
Add a note to the README on the new decorator from #17.
Mention the collect_har decorator.
Point people to the rube.fedora readme from rube.core.
Mention gcc-g++ in the README.  Fixes #7.
Make a note about how we dont test sites with no stg instance.
Remove yum -y
Merge pull request #18 from fedora-infra/feature/updated-readme

Feature/updated readme