Disable MRI 1.9.3 in Travis builds

It errors because of a too new version of rack that only supports 
Ruby >= 2.0. This will be addressed down the road as it's probably just 
a matter of tweaking the test stuff that's present in the Gemfile.

Author: elia

.travis.yml

@@ -8,8 +8,8 @@ matrix:
   fast_finish: true
 
   include:
-    - rvm: 1.9.3
-      env: RUN=default
+    # - rvm: 1.9.3
+    #   env: RUN=default
     - rvm: 2.0.0
       env: RUN=default
     - rvm: 2.1.0