Unit tests based on junit

This builds on PR #12
It adds junit based unit tests. The added tests use quasi quotes, which come with a (only compile time) dependency on the macro paradise compiler plugin and also require scala 2.10.3. In order to run on reflection trees, this also includes an adaptation of @amirsh's https://github.com/amirsh/sprinter-macro-test/blob/a15a6e33e62a6b0cc04319c050a16ec095fab890/src/main/scala/PrettyPrinter.scala