Pry version incompatibility

[estryker]

I needed to add the following to my Gemfile in order to have this gem work:
gem 'pry', '0.9.10'

Otherwise, bundler installed the latest version of pry (version 0.10.1 as of this writing) which is incompatible. The method 'inject_sticky_locals' has been renamed to 'inject_sticky_locals!' in this later version of pry.