v2.3.1.RELEASE

Change log:

2dd811f Add build scan to travis
6bf6008 Add opt-in integration with Gradle's build scans
b53c934 Fix Sonar issues
457e63a GH-1260: Add exception classification to DARP
37a1b5b Remove unused field from FailedRecordTracker
fe7f8c1 Fix duplicated link in Docs
0ae9dcc GH-1259: Failed recovery with no retry
9abc873 GH-1259: Handle Failed Record Recovery
0feba30 Upgrade samples