Travis: Replaced Ruby 2.1.0 with 2.1.2. Removed jruby-head because

DavidEGrayson · DavidEGrayson · commit 9338c346860a · 2014-09-14T09:47:33.000-07:00
jruby/jruby#1792 was breaking the build.
diff --git a/.travis.yml b/.travis.yml
@@ -2,8 +2,7 @@ script: "rspec"
 rvm:
   - 1.9.3
   - 2.0.0
-  - 2.1.0
+  - 2.1.2
   - jruby-19mode
   - rbx
   - ruby-head
-  - jruby-head
