fix JavaScript master build

fixes: COREFE-229

2 things:
1. there was a problem with deprecated.test.js where node would
   run out of memory
2. When raven went to log stuff it would die because it would try
   to use window.fetch, but that is just a mocked function in jest

Change-Id: Ib8a4de3605606a9bf0496634f93bfed3731a5d1a
Reviewed-on: https://gerrit.instructure.com/206857
Reviewed-by: James Butters <jbutters@instructure.com>
Tested-by: Jenkins
QA-Review: Ryan Shaw <ryan@instructure.com>
Product-Review: Ryan Shaw <ryan@instructure.com>

app/jsx/shared/helpers/__tests__/deprecated.test.js

@@ -27,10 +27,7 @@ describe('deprecated', () => {
   let originalFn
   beforeEach(() => {
     originalFn = jest.fn()
-    jest.spyOn(global.console, 'warn').mockImplementation()
-  })
-  afterEach(() => {
-    global.console.warn.mockRestore()
+    jest.spyOn(console, 'warn').mockImplementation()
   })
 
   it('only logs deprecation message once', () => {

app/jsx/shared/helpers/setupRavenConsoleLoggingPlugin.js

@@ -37,7 +37,11 @@ export default function setupRavenConsoleLoggingPlugin(client, options) {
           }
         };
 
+        // make raven think window.fetch is unavailable so it doesn't use the mocked one
+        const fetch = window.fetch
+        delete window.fetch
         client.captureMessage(msg, data);
+        window.fetch = fetch
       }
     }
   });