Use contributorId instead or address for reimbursements

lib/contracts/reimbursement.js

@@ -23,10 +23,10 @@ class Reimbursement extends Record {
   async add (attrs, callOptions = {}) {
     const amount = parseInt(attrs.amount);
     const token = attrs.token;
-    const recipient = attrs.recipient;
+    const contributorId = attrs.contributorId;
     const expenses = attrs.expenses.map( e => new ExpenseSerializer(e) );
 
-    if (!amount > 0 || !token || token === '' || !recipient || recipient === '' || !expenses.length > 0) {
+    if (!amount > 0 || !token || token === '' || !contributorId || contributorId === '' || !expenses.length > 0) {
       return Promise.reject(new Error('Invalid data. amount, token, expenses is required.'));
     }
 
@@ -39,7 +39,7 @@ class Reimbursement extends Record {
             const reimbursement = [
               amount,
               token,
-              recipient,
+              contributorId,
               ipfsHashAttr.hashDigest,
               ipfsHashAttr.hashFunction,
               ipfsHashAttr.hashSize,