3.3 Addon Knobs is missing select

I think this is accidental, but we shouldn't be deprecating like this.

https://github.com/storybooks/storybook/blob/release/3.3/addons/knobs/src/index.js#L10
vs
https://github.com/storybooks/storybook/blob/master/addons/knobs/src/index.js#L48
