Replace promise check with Promise.resolve
Replace promise check with Promise.resolve

`Promise.resolve` will always return a promise, so instead of checking for `p` to be a promise

See: https://stackoverflow.com/questions/27746304/how-do-i-tell-if-an-object-is-a-promise
Also: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Promise#Methods
> Generally, if you don't know if a value is a promise or not, Promise.resolve(value) it instead and work with the return value as a promise.
SokratisVidros/race-until