Fixed unit tests and build system

Pull requests against this repository should now have passing builds! This also fixes tests locally. The one note is that when running the tests requests made are now NOT in test mode in order to allow for doing more requests per hour based on the account they are linked to. You can always change this behavior by enabling test mode in https://github.com/hellosign/hellosign-php-sdk/blob/v3/library/HelloSign/Test/AbstractTest.php by uncommenting line 55 (the $this->client->enableDebugMode(); ).