Remove dependency on library that breaks use on Mac and Windows

Replace camel-snake-kebab with org.tobereplaced/lettercase to make sure builds
using :aot continue to work on Mac and Windows.

See https://github.com/qerub/camel-snake-kebab/issues/15 for more details.
Tidy up changes made in commit 15aa301

* Added a description of changes in commit 15aa301 to CHANGELOG.md
* Fixed indentation in project.clj
Merge pull request #6 from jayp/master

Remove dependency on library that breaks use on Mac and Windows