added proxy support
moved test config files into a sub directory
fixed config path
have travis install dev deps
removed useless bootstrap
fixed undefined constant error

fixes #111
Update Browser.php

Fix namespace in return value in methods call() and submit() for correct IDEs autocomplete.
Update Browser.php

Change return value of methods call() and submit() to MessageInterface.
Merge pull request #115 from dinecat/master

Fix namespace in return value for methods call() and submit() of Browser class.