Build wheels

[luizirber]

As discussed in spacegraphcats/spacegraphcats#214 (comment)

Use cibuildwheel, example from sourmash: https://github.com/dib-lab/sourmash/blob/954d7292619eba9041ae1c42c175f8cbbf5ad9f7/.travis.yml#L48

[ctb]

is this still something we should do now that we have conda packaging?

[luizirber]

I think it is still nice for people not using conda (since you don't need Cython and a compiler to build it)