Put simpletest in test/ when building on Travis
Put simpletest in test/ when building on Travis

Based on the .gitignore file, I believe this is where simpletest was
supposed to go in the first place.

stripe/stripe-php,5outh/stripe-php,Nayami/stripe-php,MamunHoque/stripe-php,matthewarkin/stripe-php,iFixit/stripe-php,cruisemaniac/laravel-stripe-php-bundle,a-ankitpatel/stripe-php