Test runner is too slow and always results in a "timed out" error message

[Awurin]

Hi there. The test runner seems not to work properly. Whenever I try to run my Groovy code in the in-browser editor, I get a "timed out" error message:

[SleeplessByte]

Yesh. Same as the java-test-runner. Pinging @ErikSchierboom who can link all the relevant work done thusfar.

[ErikSchierboom]

See exercism/java-test-runner#37 for the relevant Java test runner PR.