JS: Remove Package Reference to sc2 in "Claim Rewards" tutorial

The Claim Rewards tutorial example code reference sc2. This should be removed.

https://developers.hive.io/tutorials-javascript/claim_rewards.html

• package.json
• public/index.html
• public/app.js

mentioned in commit e4a5117f

marked the checklist item package.json as completed

marked the checklist item public/index.html as completed

marked the checklist item public/app.js as completed

closed