user.node_id missing (#1001)

'node_id' attribute was missing. Hence added the attribute using add_attribute script in AuthorizedUser  and NamedUser classes. 
This fixes issue #999 .

github/NamedUser.py

@@ -59,6 +59,14 @@ class NamedUser(github.GithubObject.CompletableGithubObject):
     def __repr__(self):
         return self.get__repr__({"login": self._login.value})
 
+    @property
+    def node_id(self):
+        """
+        :type: string
+        """
+        self._completeIfNotSet(self._node_id)
+        return self._node_id.value
+
     def __hash__(self):
         return hash((self.id, self.login))
 
@@ -605,6 +613,7 @@ class NamedUser(github.GithubObject.CompletableGithubObject):
         self._location = github.GithubObject.NotSet
         self._login = github.GithubObject.NotSet
         self._name = github.GithubObject.NotSet
+        self._node_id = github.GithubObject.NotSet
         self._organizations_url = github.GithubObject.NotSet
         self._owned_private_repos = github.GithubObject.NotSet
         self._permissions = github.GithubObject.NotSet
@@ -668,6 +677,8 @@ class NamedUser(github.GithubObject.CompletableGithubObject):
             self._login = self._makeStringAttribute(attributes["login"])
         if "name" in attributes:  # pragma no branch
             self._name = self._makeStringAttribute(attributes["name"])
+        if "node_id" in attributes:  # pragma no branch
+            self._node_id = self._makeStringAttribute(attributes["node_id"])
         if "organizations_url" in attributes:  # pragma no branch
             self._organizations_url = self._makeStringAttribute(attributes["organizations_url"])
         if "owned_private_repos" in attributes:  # pragma no branch