Dependency updates, fixes required for successful release (#1966)

* A number of fixes required for successful build after upgrades

- extract now takes an absolute directory only
- something changed, so we now need to force NODE_ENV=production; we use
  electron-is-dev for this
- electron-builder, electron-publisher-s3, and electron-updater are now
  updated to their latest available versions

* Add direct dependency on extract-zip, since we use it directly

* Load 'config' module after we've modified NODE_ENV

* Downgrade electron-builder due to bug, downgrade icon-maker too

The latest electron-builder came with a fix for one of our bugs as well
as a new bug that blocks builds on Windows: https://github.com/electron-userland/electron-builder/issues/2462

There's no good reason to upgrade icon-maker. And a good reason to keep at the version on github: https://github.com/jaretburkett/electron-icon-maker/issues/7

Gruntfile.js

@@ -299,7 +299,7 @@ module.exports = function(grunt) {
             response.pipe(file);
             file.on('finish', function() {
               file.close(function() {
-                extract(dest, {dir: 'release/' + extractedTo}, cb);
+                extract(dest, {dir: path.join(__dirname, 'release', extractedTo)}, cb);
               });
             });
           }