[INFO] --- exec-maven-plugin:1.6.0:exec (invoker-generator) @ jruby-openssl ---
Exception in thread "main" java.lang.UnsupportedClassVersionError: JRuby requires Java 7 or higher
       at org.jruby.RubyInstanceConfig.initGlobalJavaVersion(RubyInstanceConfig.java:1897)
       at org.jruby.RubyInstanceConfig.<clinit>(RubyInstanceConfig.java:1661)
       at org.jruby.internal.runtime.methods.InvocationMethodFactory.getAnnotatedMethodClass(InvocationMethodFactory.java:255)
       at org.jruby.anno.InvokerGenerator.main(InvokerGenerator.java:84)
[ERROR] Command execution failed.