Always add team extension methods

- This is needed for rspec to work and when no key is specified
- Small addition to README.
- Added rvmrc to .gitignore
- Bumped version to 1.1

https://thinkneardev.atlassian.net/browse/REX-1237
Merge pull request #3 from KamilMroczek/add_honeybadger_team_always

Always add team extension methods
Added default args to newly created methods.

- Bumped version to 1.2

https://thinkneardev.atlassian.net/browse/REX-1187
Merge pull request #4 from KamilMroczek/default_args

Added default args to newly created methods.
Added Heroku config line to README