Add kredits-formatter and additionally format balance

This adds a `balanceInt` value to the contributor data that has the
token balance formatted as full Kredits. (similar to Ether)

lib/contracts/contributor.js

@@ -1,5 +1,6 @@
 const Record = require('./record');
 const ContributorSerializer = require('../serializers/contributor');
+const KreditsFormatter = require('../utils/kredits-formatter');
 
 class Contributor extends Record {
   get count () {
@@ -8,9 +9,13 @@ class Contributor extends Record {
 
   getById(id) {
     return this.functions.getContributorById(id)
-      .then((data) => {
+      .then(data => {
         return this.ipfs.catAndMerge(data, ContributorSerializer.deserialize);
-      });
+      })
+      .then(data => {
+        data.balanceInt = KreditsFormatter(data.balance);
+        return Promise.resolve(data);
+      })
   }
 
   filterByAccount(search) {

lib/utils/kredits-formatter.js

@@ -0,0 +1,10 @@
+const ethersUtils = require('ethers').utils;
+
+module.exports = function (value, options = {}) {
+  let etherValue = ethersUtils.formatEther(value);
+  if (options.asFloat) {
+    return parseFloat(etherValue);
+  } else {
+    return parseInt(etherValue);
+  }
+}