Revert "rewrite test"

This reverts commit ee87151179030895294b750a25932c44a1f2a3cb.
Use groovy 2.3.0-beta-1
fix null safety issue

See http://jira.codehaus.org/browse/GROOVY-6666
Merge branch 'master' into groovy_2.3_jdk8
update tests

Restore 1 test which is fixed now and restore another that was restored prematurely