Simplify versioning
Revert "Fixed version model name in gnip-rules.rb"

This reverts commit 3fdd6eb86bb7892e0285214f5e893e24da6a9fc1.
Revert "Ah, screw it.  Declaring version manually"

This reverts commit eb176b5da6741b5aa39b12a5a68c53911eeaa930.