Improve logging further

[xfouloux]

Include a logging option INFO or DEBUG maybe in each captcha provider in the form of (not really sure of the code)

import log from '../log'
...
...
export default async function solve ............................. : Promise<string> {
  log.info(`Solving your Challenge using provider xxxxxx`);
...
...
}

That way we can be sure the solver function is being used to return the chalenge