* Bump `regexp_parser` dependency
* Simplify `regexp_parser` call side
* Fix corpus checkout indeterminism
* Checkin Gemfile.lock for deterministic builds
* Set circle ruby to 2.3.3
* Adjust metrics
* Add initial integration spec on method matching
* Yard and Heckle coverage is at 100% (heckle cov is disputable)
* Rcov does not really make sense as MRI 1.8 cannot reach all code
paths.