Metrics

[gdude2002]

This relates to https://github.com/UltrosBot/Ultros/issues/41

Just some fairly simple metrics. It should do the following:

• Store all metrics in a publically-accessible way
  • Use a database, generate tables
• Generate a UUID for each user that generates metrics
  • These UUIDs should not be public
• Provide API methods for getting metrics
  • Again, no UUIDs should be used here
• Provide a way for users to remove their metrics (automatically if possible)

[gdude2002]

Done.