Update REST Controller tests to validate date formats in job search r…

…esults

Update REST Controller tests to validate date formats

Upgrade Spring Boot and Platform

Update JobMonitor to use exponential back-off to check on job completion

Add cluster and command tags on timing metrics at job completion

Upgrade Gradle to 4.6 for consistency with master to reuse caches and…

… daemons

Make job tags order deterministic in tests

Tweak build verbosity for test execution

Increase verbosity of test tasks for CI build. Print each test method outcome (pass/skip/fail).

Update jquery dependency

Add terminated cluster deletion, unused file deletion and unused tag …

…deletion to the database cleanup task