fix(builder): show production build errors

lib/builder/builder.js

@@ -536,11 +536,6 @@ module.exports = class Builder {
               console.error(err) // eslint-disable-line no-console
               return reject(err)
             }
-
-            /* istanbul ignore if */
-            if (stats.hasErrors()) {
-              return reject(new Error('Webpack build exited with errors'))
-            }
           })
         })
     )