Merge pull request #132 from asinyagin/master

#132: pull request Issue #131 was fixed
Issue #122 Repo.hooks() was implemented
Merge pull request #134 from longtimeago/122

#134: pull request Issue #122 Repo.hooks() was implemented
Issue #128 MkGists.create() bug was fixed. Regression test was added
Merge pull request #135 from longtimeago/128

#135: pull request Issue #128 MkGists.create() bug was fixed
Issue #123 Repo.releases() was implemented
Merge pull request #136 from longtimeago/123

#136: pull request Issue #123 Repo.releases() was implemented