function Backoff(opts) {
	  opts = opts || {};
	  this.ms = opts.min || 100;
	  this.max = opts.max || 10000;
	  this.factor = opts.factor || 2;
	  this.jitter = opts.jitter > 0 && opts.jitter <= 1 ? opts.jitter : 0;
	  this.attempts = 0;
	}
Initialize backoff timer with `opts`.

- `min` initial timeout in milliseconds [100]
- `max` max timeout [10000]
- `jitter` [0]
- `factor` [2]

@param {Object} opts
@api public