Add the output of "jake test --cov" to gitignore.
Add how to run the tests and get test coverage to CONTRIBUTING. Not my finest writing, but a start at least hopefully :-)
Merge branch 'master' of github.com:danzel/Leaflet

* 'master' of github.com:danzel/Leaflet:
  Add how to run the tests and get test coverage to CONTRIBUTING. Not my finest writing, but a start at least hopefully :-)
  Add the output of "jake test --cov" to gitignore.
improve contribution guide, update tests/coverage notes