Deploy upgradeable Karma contract to ropsten testnet

migrations/5_upgrade_karma.js

@@ -0,0 +1,9 @@
+const { upgradeProxy } = require('@openzeppelin/truffle-upgrades');
+
+const KarmaV2 = artifacts.require('KarmaV2');
+const KarmaV3 = artifacts.require('KarmaV3');
+
+module.exports = async function (deployer) {
+    const existing = await KarmaV2.deployed();
+    await upgradeProxy(existing.address, KarmaV3, { deployer });
+};