Automatic reward fetching

[CoasterFreakDE]

is blocked by #6

Describe the solution you'd like
You should be able to add automatic reward fetching for some presets through API calls.

e.g. You have an API that can create licenses for a certain product. The system has an open API with bearer token.

/drop configure preset mylicense type: 'rest' url: 'https://my-cool-api.stuff/license'
      method: 'get' authorization: 'Bearer MYTOKEN'

When a drop with this preset is performed, the bot should call this api and reading it's answer.