Use getContributorById call to get contributor data

This new call also returns the balance of the contributor so we don't
have to make an extra call to the token contract.

app/services/kredits.js

@@ -116,7 +116,7 @@ export default Service.extend({
 
   getContributorById(id) {
     return this.get('contributorsContract')
-      .then((contract) => contract.contributors(id))
+      .then((contract) => contract.getContributorById(id))
       // Set basic data
       .then(({
           account: address,
@@ -124,8 +124,8 @@ export default Service.extend({
           hashSize,
           isCore,
           profileHash: digest,
+          balance
         }) => {
-
         let isCurrentUser = this.get('currentUserAccounts').includes(address);
         let profileHash = this.getMultihashFromBytes32({
           digest,
@@ -139,17 +139,9 @@ export default Service.extend({
           isCore,
           isCurrentUser,
           profileHash,
+          balance: balance.toNumber()
         };
       })
-      // Add the balance
-      .then((data) => {
-        return this.get('tokenContract')
-          .then((contract) => contract.balanceOf(data.address))
-          .then((balance) => {
-            data.balance = balance.toNumber();
-            return data;
-          });
-      })
       // Fetch IPFS data if available
       .then(this.loadContributorProfile.bind(this))
       .then((attributes) => {