Support for mocha with chai and mocha with should for testing.

You can select the testing library to use using the `-t` flag: `jasmine`, `mocha-should` or `mocha-chai`. The default library is `jasmine` to change that use, e.g. `tishadow config -t mocha-should`.

All libraries are included and required, just write the specs.

Credits to @tonylukasavage for his work on https://github.com/tonylukasavage/ti-mocha