This is a follow-up to FINERACT-809 to upgrade rest-assured again, after FINERACT-846.
Detect, and fix, duplicate classes from similar JARs on the Fineract classpath
Upgrade rest-assured to version 3.3.0 (not later, due to Java 8/11)
Upgrade Fineract 1.x to Java 11 and Upgrade Dependencies to latest versions
Drop more fixed version numbers in build.gradle by replacing them with Spring BOM version
Improve Java API style used for writing integration tests in Fineract