Remove original java source files. These files will be generated by jruby compiler.
ref: https://github.com/norikra/norikra/issues/7
Re-implemented udf-mock in pure jruby.
ref: https://github.com/norikra/norikra/issues/7
Merge pull request #2 from kawamuray/pure_jruby

Re-implemented udf-mock in pure jruby