Check last order status

[mwan-ep]

Description:

This adds the GetPreviousPurchaseStatus Intent. When this intent is triggered Alexa will retrieve the most recent order and return the order number, and status of the order.

Example script:
User: "What is the status of my last order?"
Alexa: "Your previous order, order number 20100, is in progress.

Linting:

• No linting errors

Tests:

• Manual tests
  Ran skill with a user who has an order checked out and confirm the script works.
  Documentation:

• Requires documentation updates
  Need to add this Intent to the Intents page: https://documentation.elasticpath.com/alexa-skill/docs/intents.html