Update .travis.yml

Excluding Ruby 1.8.7 temporarily as it is causing Travis CI issues with Coveralls and Bundler (rubygems/bundler#2784)

.travis.yml

@@ -4,6 +4,7 @@ rvm:
   - 1.9.3
   - 1.8.7
   - ree
+  - jruby-18mode
   - jruby-19mode
   - rbx-2.1.1
 gemfile:
@@ -17,8 +18,14 @@ matrix:
       gemfile: ruby187.Gemfile
     - rvm: 1.8.7
       gemfile: Gemfile
+    - rvm: 1.8.7
+      gemfile: ruby187.Gemfile
     - rvm: ree
       gemfile: Gemfile
+    - rvm: jruby-18mode
+      gemfile: Gemfile
+    - rvm: jruby-18mode
+      gemfile: ruby187.Gemfile
     - rvm: jruby-19mode
       gemfile: ruby187.Gemfile
     - rvm: rbx-2.1.1