Added Project Lists to ruby wrapper.

Added Project Lists to the Ruby wrapper since I needed it for a project.

On a separate note I also had to use the patch from @matt-stuart in [this commit](https://github.com/matt-stuart/cashboard-rb/commit/bafe5597c201803a4dc3fb75252454a10a21ad2c) to get the Ruby wrapper to work with endpoints that sometimes return one object directly instead of an array when there's only one item to return.