Fix Travis CI settings

Squashed commit of the following:

commit d2ad908af894e9d5961673f56cba2decca025cf1
Author: Toshiki Takeuchi <take@xcoo.jp>
Date:   Tue Aug 5 14:02:29 2014 +0900

    Fix travis settings

commit ab1095fcc6b8f20036212da98269c49a77f39778
Author: Toshiki Takeuchi <take@xcoo.jp>
Date:   Tue Aug 5 13:27:19 2014 +0900

    Fix Travis settings

commit e727fdcead53af841dcd60b89ddf65afa5af6700
Author: Toshiki Takeuchi <take@xcoo.jp>
Date:   Tue Aug 5 13:12:55 2014 +0900

    Fix Travis settings