Update README.md

Change `cloudant.use` to `nano.use`.
diff --git a/README.md b/README.md
index 8ca9dd3..90c10bb 100644
--- a/README.md
+++ b/README.md
@@ -411,7 +411,7 @@
 The `insert` function can also be used with the method signature `db.insert(doc,[callback])`, where the `doc` contains the `_id` field e.g.
 
 ~~~ js
-var alice = cloudant.use('alice')
+var alice = nano.use('alice')
 alice.insert({ _id: 'myid', crazy: true }, function(err, body) {
   if (!err)
     console.log(body)
@@ -421,7 +421,7 @@
 and also used to update an existing document, by including the `_rev` token in the document being saved:
 
 ~~~ js
-var alice = cloudant.use('alice')
+var alice = nano.use('alice')
 alice.insert({ _id: 'myid', _rev: '1-23202479633c2b380f79507a776743d5', crazy: false }, function(err, body) {
   if (!err)
     console.log(body)