Merge pull request #7 from jcabi/master

merge from master to my branch
Issue #75 Unit test for GhUser was implemented
Merge pull request #8 from jcabi/master

merge from master to my branch
Issue #59 Inner Class defines compareTo(...) and uses Object.equals()
Issue #59 fixed
Merge pull request #89 from lthuangiang/issue59

#89: pull request Issue #59 Inner Class defines compareTo(...) and uses Object.equals()