- **Breaking:** Changed `STRING.to_ary` to return an array of characters instead of splitting the string
- Use the new builtin `$split` function to split a string on whitespace into an array of words
- **Breaking:** Changed `Context` to use keyword-only arguments
- **Breaking:** Dropped support for Python versions 3.4 and 3.5
- **Breaking:** Invalid floating point literals now raise `FloatSyntaxError` instead of `RuleSyntaxError`
- **Breaking:** Moved `rule_engine.engine.Builtins` to `rule_engine.builtins.Builtins`
- Added the new `FUNCTION` data type