Added some of behat's most immediately useful command line options to pass through

You can now add some of behat's own command line options, which will be passed through:

`--format=format`
`--tags=tag-filter-expression`
`--no-snippets`
`--profile=profile-name-from-behat-yml`
Merge pull request #2 from atticmedia/master

Add behat options to behat:run