.travis.yml in opentok-2.4.0.beta.1 vs .travis.yml in opentok-2.4.0

@@ -7,9 +7,10 @@
 rvm:
 - 1.9.3
 - 2.0.0
 - 2.1.0
 - 2.2.0
-- rbx-2
+- 2.3.0
+- 2.4.0
 notifications:
   slack:
     secure: agVll2R9PTPvJMcUgbvOh9eGt60zGDc8kPUwEsiQr828rCgXh/ZxD5irYDyKQg3ZsS8+f3MjFCwzU7uQALkia2pDrie9d8g8m1dt4Q5U7Qm6QecshvE0U9JwbB5Ngxaftbqyf0XEFrE7CKs7RI1BzFRpe8m+fdZgfwccX8Gb7pc=