Add Knack support

[michaelstephens]

Game Reviews

As a User, I'd like to be able to ask randbot to have knack related features

Requirements

Primary

• Asking for knack gives a knack gif
• Asking for a knack bomb gives multiple knack gifs
  • MAX LIMIT 10
• Integrate with giphy to pull knack gifs

Secondary

• Responds with a knack gif after any instance of knack said?

Criteria for acceptance

• Calling @randbot knack me should give me a knack gif
• Calling @randbot knack bomb [X] should give me up to 10 knack gifs