Pippi should ignore gems directories

[dankohn]

Hi, pippi is now working for me, but it would be great if it offered to ignore code from gems. In fact, this would be helpful as the default option. My pippi.log reads:

/Users/dan/.rbenv/versions/2.1.2/lib/ruby/gems/2.1.0/gems/activesupport-4.1.7/lib/active_support/callbacks.rb,ReverseFollowedByEach,559
/Users/dan/.rbenv/versions/2.1.2/lib/ruby/gems/2.1.0/gems/rack-1.5.2/lib/rack/builder.rb,ReverseFollowedByEach,134
/Users/dan/.rbenv/versions/2.1.2/lib/ruby/gems/2.1.0/gems/rspec-core-3.1.7/lib/rspec/core/world.rb,SelectFollowedBySize,95
/Users/dan/.rbenv/versions/2.1.2/lib/ruby/gems/2.1.0/gems/rspec-core-3.1.7/lib/rspec/core/flat_map.rb,ReverseFollowedByEach,7
/Users/dan/.rbenv/versions/2.1.2/lib/ruby/gems/2.1.0/gems/faker-1.4.3/lib/faker/bitcoin.rb,ReverseFollowedByEach,23
/Users/dan/.rbenv/versions/2.1.2/lib/ruby/gems/2.1.0/gems/activesupport-4.1.7/lib/active_support/callbacks.rb,ReverseFollowedByEach,511
/Users/dan/.rbenv/versions/2.1.2/lib/ruby/gems/2.1.0/gems/activemodel-4.1.7/lib/active_model/attribute_methods.rb,ReverseFollowedByEach,362
/Users/dan/.rbenv/versions/2.1.2/lib/ruby/gems/2.1.0/gems/cancancan-1.9.2/lib/cancan/model_adapters/active_record_adapter.rb,SelectFollowedBySize,20
/Users/dan/.rbenv/versions/2.1.2/lib/ruby/gems/2.1.0/gems/cancancan-1.9.2/lib/cancan/model_adapters/active_record_adapter.rb,ReverseFollowedByEach,24
/Users/dan/.rbenv/versions/2.1.2/lib/ruby/gems/2.1.0/gems/rspec-mocks-3.1.3/lib/rspec/mocks/space.rb,ReverseFollowedByEach,74
/Users/dan/.rbenv/versions/2.1.2/lib/ruby/gems/2.1.0/gems/cancancan-1.9.2/lib/cancan/model_adapters/active_record_adapter.rb,SelectFollowedByFirst,20
/Users/dan/.rbenv/versions/2.1.2/lib/ruby/gems/2.1.0/gems/cancancan-1.9.2/lib/cancan/model_adapters/active_record_adapter.rb,SelectFollowedByFirst,22
/Users/dan/.rbenv/versions/2.1.2/lib/ruby/gems/2.1.0/gems/paperclip-4.2.0/lib/paperclip/interpolations.rb,ReverseFollowedByEach,32
/Users/dan/.rbenv/versions/2.1.2/lib/ruby/gems/2.1.0/gems/chronic-0.10.2/lib/chronic/handler.rb,SelectFollowedBySize,66
/Users/dan/.rbenv/versions/2.1.2/lib/ruby/gems/2.1.0/gems/chronic-0.10.2/lib/chronic/handler.rb,SelectFollowedBySize,48
/Users/dan/.rbenv/versions/2.1.2/lib/ruby/gems/2.1.0/gems/chronic-0.10.2/lib/chronic/handler.rb,SelectFollowedBySize,57
/Users/dan/.rbenv/versions/2.1.2/lib/ruby/gems/2.1.0/gems/chronic-0.10.2/lib/chronic/handlers.rb,SelectFollowedBySize,146
/Users/dan/.rbenv/versions/2.1.2/lib/ruby/gems/2.1.0/gems/actionpack-4.1.7/lib/action_controller/metal.rb,ReverseFollowedByEach,38
/Users/dan/.rbenv/versions/2.1.2/lib/ruby/gems/2.1.0/gems/sprockets-2.11.3/lib/sprockets/asset_attributes.rb,ReverseFollowedByEach,72
/Users/dan/.rbenv/versions/2.1.2/lib/ruby/gems/2.1.0/gems/activesupport-4.1.7/lib/active_support/rescuable.rb,ReverseFollowedByEach,88

[tcopeland]

@dankohn yeah that is annoying. Maybe we should add a PIPPI_FILTER="my_app_name/app" option?