Rasa-sdk

Added
=====

- add optional [validate\_{slot}]{.title-ref} methods to [FormAction]{.title-ref}
- forms can now be deactivated during the validation function by returning
[self.deactivate()]{.title-ref}
- Function to get latest input channel from the tracker with
`tracker.get_latest_input_channel()`

Changed
=======

- `self._deactivate()` method from the `FormAction` class has been
renamed to `self.deactivate()`

Fixed
=====

- doc formatting preventing successfull rasa core travis build

Added
=====

- added Dockerfile for rasa\_core\_sdk
- add `active_form` and `latest_action_name` properties to `Tracker`
- add `FormAction.slot_mapping()` method to specify the mapping between
user input and requested slot in the form
- add helper methods `FormAction.from_entity(...)`,
`FormAction.from_intent(...)` and `FormAction.from_text(...)`
- add `FormAction.validate(...)` method to validate user input

Changed
=======

- `FormAction` class was completely refactored
- `required_fields()` is changed to `required_slots(tracker)`
- moved `FormAction.get_other_slots(...)` functionality to
`FormAction.extract_other_slots(...)`
- moved `FormAction.get_requested_slot(...)` functionality to
`FormAction.extract_requested_slot(...)`
- logic of requesting next slot can be customized in
`FormAction.request_next_slot(...)` method

Removed
=======

- `FormField` class and its subclasses

Fixed
=====

Fixed
=====

- current state call in tracker

Fixed
=====

- wrong event name for the `AgentUttered` event - due to the wrong name,
rasa core would deserialise the wrong event.