Adding Gitective [1] as a dependency and creating the class that will be
responsible for the local Git repository analysis within Groundhog.

Starting with non-parameterized commit extraction and extraction of commits from a given user.

Nothing finished just yet. Code in main package only present for current
debugging and testing purposes, once the commit message extraction is
done it will be moved to the groundhog-case-study [2] project.

[1]: https://github.com/kevinsawicki/gitective
[2]: github.com/gustavopinto/groundhog-case-study

Related to #55 and #60
searching commits with gitective
filtering commits that have altered java code. r #60
Refactoring method for counting commits that include a given file extension
Adding some documentation
Merging branch ft-new-git-module, which is not finished but the existing
work can be merged and be used to solve some questions. Related to #60.

* ft-new-git-module:
  Adding some documentation
  Refactoring method for counting commits that include a given file extension
  filtering commits that have altered java code. r #60
  searching commits with gitective
  Adding Gitective [1] as a dependency and creating the class that will be responsible for the local Git repository analysis within Groundhog.