0.9.0 release (#71)

* 0.9.0 release

* Make the changelog a markdown file.

* Format the changelog to use markdown formatting.

* Thanks, Ryan.

* Remove CI config from gemspec.

0.8.3 release

0.8.2 release.

0.8.1 release.

0.8.0 release.

0.7.8 release.

Version 0.7.7.

Actual 0.7.6 release.

0.7.5 release.

0.7.4 release.