* Add support for showing end location marker
* Cleanup Reportable method definitions
There’s no need for double splats, since they mess up method resolution, and obscure the actual - single (!) - argument - `status`, so… be gone
Also, all of the helpers return the constructed `Issue` like a behaving good methods.
* Refactor Util#affected_code
* Increase max length of trimmed lines to 120 characters
* Refactor Issue to use enum instead of a symbol for #status
* Optimize Reportable#valid?
* Add spec coverage for newly added Util methods
* Refactor DotFormatter a bit
Make text format moar in line with Crystal spec runner.
* Update README.md
