Release Name: 0.2.0

Notes:
Better error handling, small bugfix, some interface improvements and refactoring.


Changes:
Version 0.2.0
- Better error handling (i.e. error messages)
- Checking if the exiftool command can be executed at loading the lib
- New class method exiftool_version
- Added tests
- Documentation completed

Version 0.1.2
- Bugfix for Windows (Tempfile)
  Thanks to Jérome Soika for testing
- Regexes optimized (a little bit)
- New class-method MiniExiftool.writable_tags