Adds all the fields available in the coveralls documentation

added support for appveyor pull request head commit (#12)

* added support for appveyor pull request head commit

* Removed BuildTools

* Fixed bug in GitProcessGitDataResolver that added extra quotes

* Moved to single ILogger instead of logger factory

* Added logging of appveyor environment variables

* Updated to get the commit id and branch from appveyor env vars

* Added run-at timestamp

* Fixed test when running in appveyor