Return promises if callback not present

[IBMCode]

Would be great if this library return promises if a callback is not present for apis.

[ljharb]

At this point, it'd be better to make a breaking change to only return a promise, rather than accepting a callback at all.

[IBMCode]

Yeah, just for backward compatibility I suppose. For the time being, I am just wrapping mine in a promise. Bluebird promisify didn't work for me, had to do it manually.

[ljharb]

https://npmjs.com/util.promisify is also helpful.