Fixed IPv6 Validation according to https://gist.github.com/cpetschnig/294476
Fixed ERROR: 'rake/rdoctask' is obsolete and no longer supported. Use 'rdoc/task' (available in RDoc 2.4.2+) instead.
/ipaddress/Rakefile:47:in `<top (required)>'
Fixed + Added Test Cases
Update README.rdoc

Small fix
Updates Rakefile from obsolete rake/rdoctask to rdoc/task
Merge branch 'brona-master' into develop
Merge branch 'develop', fixes #32