- basic semantic versioning parser and comparator
- logic to compare if two coder versions are API compatible
- basic checking between a tested Coder version number and
  the Coder version
- resolves #89

- and also implement equals and hashCode

- use Groovy and Spock for UTs because it's much more expressive
  but at the same time there is minimum boilerplate

- use resource bundles to specify the last version of Coder
  on which the plugin was tested
- minor renames for better readability