Added functional test for _form route to the SimpleTest test, and moved chunks of WebTestBase and BrowserTestBase into WebTestTrait.
Fixed bugs to get BrowserTestBaseTest assertions passing.
Merge remote-tracking branch 'upstream/phpunit-mink' into phpunit-mink

Conflicts:
	core/modules/simpletest/src/BrowserTestBase.php
Fixed the stupid form test.
Merge pull request #5 from phenaproxima/phpunit-mink

Passing tests for BrowserTestBase