Github PR validation by Apache Jenkins

[Vlad Rozov]

Due to infrastructure changes, Apache Jenkins jobs that were triggered 
to validate Apex Core and Malhar PRs were not reported back to the 
GitHub and the PR. I made necessary changes, but it was required to move 
from one Jenkins plugin to another. If you notice that Jenkins jobs are 
still not reported back to the github, please let me know.

Thank you,
Vlad