mz should be a dependency, not a devDependency

[danoc]

Hello!

Thanks for this great plugin.

When I try to use it, Node complains that it can't find mz. I've confirmed that it doesn't get installed. I imagine this is because mz is currently a devDependency, not a dependency.

As a workaround, I've installed mz with yarn add mz but I'd love it it was included with this package.

Thanks!

[sergioramos]

thank you for noticing that @danoc 👍