gatsby 0.12.18

A bug fixin' we go

on Node.js NPM

Some nice bug fixes of some long-standing annoyances by @mojodna and @TheAncientGoat

• @mojodna finally got Webpack's publicPath working across all the build steps and adds the linkPrefix as needed #502. Fixed #392 and #473
• @TheAncientGoat noticed that Firebase was failing during a server render and traced it to Firebase (and certain other isomorphic packages) using different packages on the server and in the browser and fixed the Webpack config for this in #512
• @KyleAMathews back-ported some Webpack config from his 1.0 work to add file/url loader support for more file types.