Issue 492 RtFork class implemented.
Issue 492 Fixes after code review
Issue 492 RtForkTest refactored. Duplication in MkAnswer creation was replaced with method extraction.
issue 508 fixed
Merge pull request #510 from aistomin/Issue-492

#510: pull request Issue 492 RtFork class implemented.
Merge pull request #522 from svarovski/issue-508

#522: pull request issue 508 fixed
Merge pull request #57 from jcabi/master

merge from master to my branch