Version 0.2.0

Added

• Added custom exceptions.
• Added en language tests.
• Added addition and subtraction grammar.
• Added shorthand 'd' for day and 'w' for week.
• Added support for returning double and Duration from parse.
• Added tryParse which is a nullable alternative to parse.
• Adds support for duration "from" datetime
  • Note that raw datetime parsing (such as 00:00) is still missing
• Added ability to map to comma from data.

Changed

• Unrecognized tokens now return [TokenType.CT_ERROR].
• Terminate on error in compiler.
• Value no longer relies on subclasses.

Fixes

• Fixed rechron_dev not matching with library declaration.
• Fixed dependency linking from rechron to rechron_dev.
• Removed aliases from grammar file.
• Removed unused 'and' token.