compile substance with webpack

webpack/babel-includes.js

@@ -4,7 +4,8 @@ const fs = require('fs')
 var babelIncludes = [
   new RegExp(path.join(__dirname, '../node_modules/pubsweet-frontend/src')),
   new RegExp(path.join(__dirname, '../app')),
-  new RegExp(path.join(__dirname, '../node_modules/pubsweet-.*'))
+  new RegExp(path.join(__dirname, '../node_modules/pubsweet-.*')),
+  new RegExp(path.join(__dirname, '../node_modules/substance'))
 ]
 
 let componentsDir = path.resolve(__dirname, '..', 'node_modules')