Make private hint for classes, methods and fields.
Added tests for protected method and field.
Use builtin FixFactory.
Add public, protected and package protected modifiers.
Merge branch 'modifiers_hints' of https://github.com/rasa-silva/nb-additional-hints into rasa-silva-modifiers_hints
issue #22: new hint "change modifiers" - Pull Request by https://github.com/rasa-silva

* updated tests
* updated doc, license headers and version
Merge branch 'rasa-silva-modifiers_hints'

* rasa-silva-modifiers_hints:
  issue #22: new hint "change modifiers" - Pull Request by https://github.com/rasa-silva
  Add public, protected and package protected modifiers.
  Use builtin FixFactory.
  Added tests for protected method and field.
  Make private hint for classes, methods and fields.
[package] provide 1.2.0-SN