Readme: Removed 'email' as possible means of authenticating users
diff --git a/README.md b/README.md
index e630a3a..e0abd6e 100644
--- a/README.md
+++ b/README.md
@@ -293,7 +293,6 @@
 ```js
 Usergrid.authenticateUser({
     username: '<username>',
-    email: '<email-address>', // either username or email is required
     password: '<password>'
 }, function(error, usergridResponse, token) {
     // Usergrid.currentUser is set to the authenticated user and the token is stored within that context
@@ -305,7 +304,6 @@
 ```js
 Usergrid.authenticateUser({
     username: '<username>',
-    email: '<email-address>', // either username or email is required
     password: '<password>'
 }, false, function(error, usergridResponse, token) {