Merge Karma into one contract

+ Update README contract addresses to reflect new upgradeable version on ropsten
+ Remove functions added to Karma that I was using to test the upgrade process
+ Add test for deploying Karma proxy successfully

migrations/4_upgrade_karma.js

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

migrations/5_upgrade_karma.js

@@ -1,9 +0,0 @@
-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 });
-};