Added ID to contacts and services; removed dupe

Added missing IDs to example responses for contacts and services
Removed a duplicative field in the events object

Author: Josh Sager

docs/src/data/objects/managedcontact.yaml

@@ -4,6 +4,10 @@ prefix: managed/contacts
 description: >
   A list of people we can contact if we require further information regarding your Managed service.
 schema:
+  id:
+    type: Integer
+    value: 123
+    description: This contact's ID.
   name:
     value: John Q. Public
     type: String

docs/src/data/objects/managedservice.yaml

@@ -4,6 +4,10 @@ prefix: managed/services
 description: >
   Managed Service objects describe monitoring services set up for your Linodes.
 schema:
+  id:
+    type: Integer
+    value: 123
+    description: This service's ID.
   created:
     type: Datetime
     value: 2017-10-31T11:12:21

src/data/objects/event.yaml

@@ -39,7 +39,6 @@ schema:
     description: >
       The action that caused this event.
   username:
-    type: String
     type: String
     value: example_user
     description: >