Move sources to the proper directory path according to their package declaration.

This commit places all sources in the conventional location:

- src/main/scala for Scala sources
— src/test/scala for tests (and removes `test` package when it was used)
- src/{main|test}/resources for, well, resources, replacing `resources` and `test-resources`
Merge pull request #4 from dragos/issue/use-conventional-directory-layout

Use convenational layout