Add semicolon to source-map-support banner to fix 'require() is not a function' error (#162)

Author: nkohari

packages/backpack-core/config/webpack.config.js

@@ -125,7 +125,7 @@ module.exports = options => {
               'source-map-support/register'
             : // It's not under the project, it's linked via lerna.
               require.resolve('source-map-support/register')
-        }')`,
+        }');`,
       }),
       // The FriendlyErrorsWebpackPlugin (when combined with source-maps)
       // gives Backpack its human-readable error messages.