integrated slack to travis

 language: node_js
 node_js:
 - '0.10'
-- '0.11'
 script: npm run-script test-travis
 after_script: npm install coveralls@2 && cat ./coverage/lcov.info | coveralls
 notifications:
@@ -14,3 +13,5 @@ notifications:
   hipchat:
     rooms:
       secure: SZAghgIWk6b8rpItdkjSY8UJtTW8E8AIYE5KkTGa9FiV0/q9kTHIAiqxBAQyIgF9IVsrO2NZdO9FrsiKjkSUPXbkonxtuqptl2c7bJLm2gUNmku2DfG0hn8TY50MXxGpiyEySoxcX4igQTzSZlJM81T0EI+L0PQJJXUKEJGuadY=
+  slack:
+    secure: 3uMd7XP25L2pPQ+4yzWmlSwsTBaiTERvTrA/e+Nz69g+nMpNviMVMRtLF/wlp01eehgNJ9InVdQ7Bq+MqS4eJPtqjVass7a3IplMIvjugMPlzw9eCEDxrxdbW649jw2esVKOj0eB40zhLrsV1AtxPyENIWeOn8uvVNjMLhiNiUs=