add support to update permissions

README.md

@@ -224,7 +224,7 @@ Delete permission by specifying description
 Body
 ```
 {
-    "Description":"Readonly access to default safe"
+    "Description": "Readonly access to default safe"
 
 }
 ```
@@ -234,7 +234,7 @@ Delete permission by specifying permission id
 Body
 ```
 {
-    "permissionId":2
+    "permissionId": 2
 
 }
 ```
@@ -243,6 +243,22 @@ Deletes a permission mapping either a user or a group to a safe. Either the perm
 
 Deleting a permission should be performed prior to deleting any groups specified in that permission.
 
+#### Update Permission
+**POST** `/api/admin/permission/update`
+
+Change description of permission
+
+Body
+```
+{
+    "permissionId": 2
+    "Description": "New Permission Description"
+
+}
+```
+
+Updates an existing permission. The permissionId must be specified. This operation can only be performed by a user that is admin enabled. 
+
 ### Group Operations
 
 #### List Groups