Update Pull request Github check

[vitaliimelnychuk]

The idea is to have Github status check with coverage percentage along with comment that we already have

Implementation

As an example we can use this article https://www.infoq.com/news/2018/05/github-checks-api/
and documentation: https://developer.github.com/changes/2018-05-07-new-checks-api-public-beta/

Usability

It will be great feature as we can split process of running code coverage and separate check with report with code coverage summary.