travis: test with MRI 2.2.0 and RBX 2.4.1
travis: test with MRI 2.2.0 and RBX 2.4.1

rstacruz/i18n-tasks,bartimaeus/i18n-tasks,rstacruz/i18n-tasks,glebm/i18n-tasks,2947721120/i18n-tasks,rstacruz/i18n-tasks