update dependencies
add pry to gemfile
Update CONTRIBUTE! in README.md .
Merge pull request #3 from yui-knk/change-readme

Update CONTRIBUTE! in README.md .
add rb-readline runtime dep. closes #2
readme fix
pry-bond is now running on the pry head version without errors

- rename Pry::Bond to Pry::BondCompleter to avoid name clashing
- Bond's completions have now higher precedence than Pry's completions
- moving the closure into the action option
- add Bond's standard completions to Pry's command set completions, as
it was the case for earlier versions of Pry