V0.5 wip

Preparing for v0.5 release, [see this issue](https://github.com/mroth/lolcommits/issues/113) for details;

progress so far
 - [x] update changelog and version
 - [] investigate issues with wacaw binary on latest MacBook air (@matthutchinson)
 - [ ] all tests pass on build machine without errors
 - [ ] push built gem to rubygems
 - [ ] push git tags to github
 - [ ] manually tag "release" via github feature and add notes from changelog