Adding behat tags to valid and recommended tags

Adding them at the beginning following ASCII
chars order.
New rule to validate tags against paths.

Some of the tags are only valid under certain
directories, this new rule is built on top of
existing valid and recommended and verifies
that the tags are only used into valid paths
(usually behat/phpunit paths).
Merge pull request #17 from stronk7/behat_valid_tags

Behat valid tags
Make form appear properly in UI displaying all fields
Merge pull request #19 from marinaglancy/master

Make form appear properly in UI displaying all fields
MDLSITE-3282 don't complain about plain test methods

It has become sort of a de-facto standard to have no phpdocs on test
methods in Moodle phpunit tests. This makes a lot of sense because:

* The test name should be the descriptive part - as it also is the most
 commonly shared part of any failure
* Extensive phpdoc blocks that they easily get outdated as someone adds
 another few assertions to address whats going
Merge pull request #20 from danpoltawski/MDLSITE-3282

MDLSITE-3282 don't complain about plain test methods