Merge pull request #3 from jcabi/master

merge from master to one
Issue #32 Created unit test for class GhMarkdown.
Issue #32 Code formatting modifications.
Issue #64 Created GhGistsTest class, canCreateFiles() test method.
Issue #64 Added canIterateThroughGists, canRetrieveSpecificGist test
methods.
Issue #64 Updated @todo puzzle comment in GhGists.java.
Issue #31  was implemented
Issue #31  fixed
Merge pull request #67 from carlosmiranda/64

#67: pull request Issue #64 Unit test has been created for GhGists
Merge pull request #66 from carlosmiranda/32

#66: pull request Issue #32 Created unit test for class GhMarkdown.
Merge pull request #68 from lthuangiang/master

#68: pull request Issue #31 was implemented