Review test execution concurrency
The issue was first observed when new tests were implemented for #83 (closed).
The solution reuseForks:false, deletes each fork after executing, requiring a cold JVM with each test. Should try:
- reuseForks, smaller -Xmx1g (with 4-6 forks) or even smaller -Xmx768m
- reuseForks:false, forkCount:2-3