Adding ElicitSlotDirective through ASK Python SDK

elicit_slot_handler_example.py

## Example directive, from https://developer.amazon.com/docs/custom-skills/dialog-interface-reference.html#elicitslot

from ask_sdk_model.dialog import ElicitSlotDirective
from ask_sdk_model import (
    Intent, IntentConfirmationStatus, Slot, SlotConfirmationStatus)

directive = ElicitSlotDirective(
    slot_to_elicit="fromCity",
    updated_intent=Intent(
        name="planMyTrip",
        confirmation_status=IntentConfirmationStatus.NONE,
        slots={
            "toCity": Slot(
                name="toCity",
                confirmation_status=SlotConfirmationStatus.NONE),
            "travelDate": Slot(
                name="travelDate",
                confirmation_status=SlotConfirmationStatus.NONE,
                value="2017-04-21")
        }
    )
)

handler_input.response_builder.speak(
    "200 dollors, do you want to pay?").ask(
    "do you want to pay").add_directive(directive)


## Additionally, if there is a need to add resolutions in the updated intent,
## the user can add the following code
## Based on the example provided here : https://developer.amazon.com/blogs/alexa/post/5de2b24d-d932-4c6f-950d-d09d8ffdf4d4/entity-resolution-and-slot-validation

from ask_sdk_model.slu.entityresolution import (
    Resolutions,Resolution, ValueWrapper, Value, Status, StatusCode)

slots = {
    "WeatherType": Slot(
        name="WeatherType",
        value="shower",
        resolutions=Resolutions(
            resolutions_per_authority=[
                Resolution(
                    authority="amzn1.er-authority.echo-sdk.<skill_id>.WEATHER_TYPE", 
                    status=Status(
                        code=StatusCode.ER_SUCCESS_MATCH), 
                    values=[
                        ValueWrapper(
                            value=Value(
                                name="rain", 
                                id="RAIN"
                            )
                        )
                    ]
                )
            ]
        )
    )
}