revert commits accidentally added from "Added support for grouping tasks by challenge"

So sorry, but I accidentally pushed some commits I'd been testing. :( This reverts them.

Reverts c496f94c79 ad6073220d d669db0f9a c244fe488d

test/api/v3/integration/challenges/POST-challenges_challengeId_leave.test.js

@@ -117,9 +117,7 @@ describe('POST /challenges/:challengeId/leave', () => {
       });
 
       expect(testTask).to.not.be.undefined;
-      expect(testTask.challenge).to.eql({
-        name: 'None',
-      });
+      expect(testTask.challenge).to.eql({});
     });
   });
 });

test/api/v3/integration/groups/GET-groups_groupId_members.test.js

@@ -84,7 +84,7 @@ describe('GET /groups/:groupId/members', () => {
     expect(Object.keys(memberRes.auth)).to.eql(['timestamps']);
     expect(Object.keys(memberRes.preferences).sort()).to.eql([
       'size', 'hair', 'skin', 'shirt',
-      'chair', 'costume', 'sleep', 'background', 'tasks',
+      'chair', 'costume', 'sleep', 'background',
     ].sort());
 
     expect(memberRes.stats.maxMP).to.exist;

test/api/v3/integration/members/GET-members_id.test.js

@@ -37,7 +37,7 @@ describe('GET /members/:memberId', () => {
     expect(Object.keys(memberRes.auth)).to.eql(['timestamps']);
     expect(Object.keys(memberRes.preferences).sort()).to.eql([
       'size', 'hair', 'skin', 'shirt',
-      'chair', 'costume', 'sleep', 'background', 'tasks',
+      'chair', 'costume', 'sleep', 'background',
     ].sort());
 
     expect(memberRes.stats.maxMP).to.exist;