Merge pull request #46 from jcabi/master

merge from master to my repo
MkReleases remove method implemented.
MkReleases remove method implemented. Style fix.
removed puzzle definition
Issue #430 RepoCommit interface was added
Merge pull request #47 from jcabi/master

merge from master to my repo
Issue #470 - MkPullComments should be able to fetch a single pull comment
Merge pull request #482 from lthuangiang/470

#482: pull request Issue #470 - MkPullComments should be able to fetch a single pull com…
Merge pull request #477 from longtimeago/430

#477: pull request Issue #430 RepoCommit interface was added
Merge pull request #474 from andrescandal/377

#474: pull request Issue #377 Implemented.