Add Heist Game to Bot

[benrick]

We should add a heist game that people can join in during chat.

Commands: !heist - Starts or joins a heist, choosing a random role to assume. !heist [role] - Starts or joins a heist, choosing a specific role to assume.

Roles:

• Grifter (100)
• Hacker (100)
• Hitter (100)
• Thief (200)
• Tech (150)
• Carrier (50)
• Driver (50)

Possible Heists: We should choose from a random set of heists, where each one needs different roles more than others.

• Bank Robbery (Thief/Tech/Grifter, Driver, Carrier)
• Mob Bank Robbery (Thief/Tech/Grifter, Hitter, Driver, Carrier)
• Museum Heist (Thief/Grifter, Hacker, Carrier, Driver)
• Jewelry Store (Grifter/Hacker, Driver, Carrier)

[benrick]

Game should start when all roles taken.