Add travis configuration for many rubies

Gem should work with ruby >= 1.9.3

.travis.yml

@@ -1,10 +1,18 @@
+before_install:
+  - gem install bundler
+  - bundle --version
+
 rvm:
   - 1.9.3
+  - 2.0.0
+  - 2.1.0
   - ruby-head
-  - rbx-19mode
   - jruby-19mode
-env:
-   - JRUBY_OPTS="--1.9"
+  - jruby-head
+  - rbx
+
 matrix:
   allow_failures:
-    - rvm: ruby-head
+    - rvm: rbx
+    - rvm: jruby-19mode
+    - rvm: jruby-head

Gemfile

@@ -8,4 +8,8 @@ group :test do
   gem "rack-test"
   gem "rake"
   gem "coveralls", require: false
+
+  platforms :rbx do
+    gem "iconv"
+  end
 end