refactoring endtoend tests after merging with whois-db groovy tests

Refactoring to remove duplication mainly from EndToEndSpec.groovy,
BaseSpec.groovy and WhoisFixture.java. This follows the refactoring
done with commit: 9568692b9c0a80dfecc3b8ce2c3e76dbd680f9bf where
integration tests from whois-db were merged into whois-endtoend module.
re-deleting EndToEndSPec, no more needed

The file came again after pulling from origin. Initially deleted after refactoring groovy tests
(commit:707e51e211d1a5c8c9e9861a1406c04fbc7c5231)