Implemented the following tags that have been missing:
- displayBuildErrorsOnDownstreamBuilds
- blackListCommitAuthor
- GhprbCommentFile
- GhprbNoCommitStatus
Following tags are printed when the value of the key is empty:
- whiteListTargetBranches
- blackListTargetBranches
- buildDescTemplate
- triggeredStatus
- startedStatus
- statusUrl
- addTestResults
Also updated tests
Change-Id: I1e19841d88728af9ac6aa9e1c78f89fe962a583f
Signed-off-by: Eren ATAS <eatas.contractor@libertyglobal.com>