fix: all things (#124)

* fix 'Testing with Chai' 404 error

* Remove service worker and unregister old workers from clients

* Fix block name in QA and Chai intro

* Move the map to the index page

* Split test commands, have travis run format on test

* Only expand the first block

* Remove some margin from p tags on the index page

* Learn -> Curriculum link in header

* UI Fixes

* Use webpack plugin to destroy sercive worker

* Add spinner for unknown user state

* Fix map placement

* Fix vcurriculum button clicks

packages/learn/gatsby-config.js

@@ -68,7 +68,6 @@ module.exports = {
         fonts: ['Lato:400,400i,500']
       }
     },
-    'gatsby-plugin-sitemap',
-    'gatsby-plugin-offline'
+    'gatsby-plugin-sitemap'
   ]
 };