[FABRIC-763] Integration test for merging properties
Removed obsolete null-check.
Created basic AbstractProcessmanagerTest API.
[Spring Boot] Added invoice create test.
[Spring Boot] Process testing API refactoring.
Added helper method to InstallOptions.
[FABRIC-1057] Make Fabric8 compile with JDK8
FAB tests migrated from Scala to Java. They still don't work on JDK8 (OSGi/ASM/Aries problem)
FAB: Migrated tests work well with JDK7