Add JS wrapper for kredits kit

This makes it easier to deploy new DAOs and the deploy script is less
dependent on truffle

lib/abis/KreditsKit.json

@@ -0,0 +1 @@
+[{"constant":true,"inputs":[],"name":"ens","outputs":[{"name":"","type":"address"}],"payable":false,"stateMutability":"view","type":"function"},{"constant":true,"inputs":[],"name":"fac","outputs":[{"name":"","type":"address"}],"payable":false,"stateMutability":"view","type":"function"},{"constant":true,"inputs":[{"name":"appId","type":"bytes32"}],"name":"latestVersionAppBase","outputs":[{"name":"base","type":"address"}],"payable":false,"stateMutability":"view","type":"function"},{"constant":true,"inputs":[{"name":"","type":"uint256"}],"name":"appIds","outputs":[{"name":"","type":"bytes32"}],"payable":false,"stateMutability":"view","type":"function"},{"inputs":[{"name":"_fac","type":"address"},{"name":"_ens","type":"address"},{"name":"_appIds","type":"bytes32[4]"}],"payable":false,"stateMutability":"nonpayable","type":"constructor"},{"anonymous":false,"inputs":[{"indexed":false,"name":"dao","type":"address"}],"name":"DeployInstance","type":"event"},{"anonymous":false,"inputs":[{"indexed":false,"name":"dao","type":"address"},{"indexed":false,"name":"appProxy","type":"address"},{"indexed":false,"name":"appId","type":"bytes32"}],"name":"InstalledApp","type":"event"},{"anonymous":false,"inputs":[{"indexed":false,"name":"appProxy","type":"address"},{"indexed":false,"name":"appId","type":"bytes32"}],"name":"InstalledApp","type":"event"},{"constant":false,"inputs":[],"name":"newInstance","outputs":[{"name":"dao","type":"address"}],"payable":false,"stateMutability":"nonpayable","type":"function"}]

lib/kreditskit.js

@@ -0,0 +1,49 @@
+const ethers = require('ethers');
+
+const ABI = require('./abis/KreditsKit.json');
+const Addresses = require('./addresses/KreditsKit.json');
+
+class KreditsKit {
+
+  constructor(provider, signer, options = {}) {
+    let { address, abi, ipfsConfig } = options;
+
+    this.provider = provider;
+    this.signer = signer;
+    this.options = options;
+    this.address = address
+    this.abi = abi || ABI;
+  }
+
+  init() {
+    return this.provider.getNetwork().then((network) => {
+      this.address = this.address || Addresses[network.chainId.toString()];
+      this.contract = new ethers.Contract(
+        this.address,
+        this.abi,
+        (this.signer || this.provider)
+      );
+      return this;
+    });
+  }
+
+  appIdFor(contractName) {
+    // see appIds in KreditsKit.sol for more details
+    const knownContracts = ['Contribution', 'Contributor', 'Proposal', 'Token'];
+    return this.contract.functions.appIds(knownContracts.indexOf(contractName));
+  }
+
+  newDAO(options = {}) {
+    return this.contract.functions.newInstance(options).then(transaction => {
+      return transaction.wait().then(result => {
+        const deployEvent = result.events.find(e => e.event === 'DeployInstance');
+        return {
+          daoAddress: deployEvent.args.dao,
+          transactionHash: transaction.hash
+        }
+      });
+    });
+  }
+}
+
+module.exports = KreditsKit;