Update proxyquireify dep

[stuartsan]

Would it be ok to update the proxyquireify dev / peer dep in package.json to ensure that >= 1.2 is used, to take advantage of the fixed issue described here thlorenz/proxyquireify#21 and fixed by thlorenz/proxyquireify@0048897 ?

[bendrucker]

I'm going to keep the peers the way they are now. peerDeps are there for specifying API-level compatibility. Since the user is responsible for installing the peers, I'm gonna say that they're responsible for installing updates in the peers as well.