Refactor Travis tests: split configs and run in parallel.
diff --git a/ruby/travis-test.sh b/ruby/travis-test.sh
index 2ccb490..e94af80 100755
--- a/ruby/travis-test.sh
+++ b/ruby/travis-test.sh
@@ -12,8 +12,4 @@
      rake test"
 }
 
-test_version ruby-1.9
-test_version ruby-2.0
-test_version ruby-2.1
-test_version ruby-2.2
-test_version jruby
+test_version $1