Stenographer WIP
Merge branch 'cops' into stenographer

Conflicts:
	lib/pacto/core/configuration.rb
	lib/pacto/core/validation_registry.rb
	spec/unit/pacto/validation_registry_spec.rb
Stenographer whose log is replayable via Pacto::Consumer; use Pacto::Consumer replay instead of contract.execute
Make stenographer log file configurable
Do nothing if stenographer log file is nil
Merge pull request #132 from thoughtworks/stenographer

Stenographer logging and playback