Broken on Ruby 2: Bump the perftools.rb dependency for fix

[findchris]

This gem does not work with Ruby 2.0 unless the gem's dependency on perftools.rb is bumped to 2.0.1 (which fixes issues with Ruby 2 compatibility). An alternative, which I am currently doing, is to make an explicit dependency on perftools.rb (2.0.1) in my Gemfile, but that is more of a workaround than anything.

[bhb]

Thanks for reporting the issue! I've just released version 0.6.1, which updates the perftools.rb dependency to 2.0.1.

[findchris]

👍