Ignore rvmrc files
Utilize bundler for setup and update dev gems

- Update to latest rspec
- Remove check_dependencies rake task that wasn't working
- Get the rcov rake task working
- Fix rake/rdoctask deprecation warning
- Update to latest redis gem
- Add rdoc, jeweler, and rcov as dev dependencies
Update readme to contain a development setup
Clean up spec file a bit
Regenerate gemspec to use new dev gems
Drop rcov - gain ruby 1.8 and 1.9 compatibility