message: Fix allenl's username in TODO
diff: @@ -735,7 +735,7 @@ class ConcreteFunction(object):
  # In case of eager execution, function definition gets added to context
  # during construction itself.
  - # TODO(allel/shivaniagrawal): rename this to register to reflect the
  + # TODO(allenl/shivaniagrawal): rename this to register to reflect the
  # method's functionality better. Remove register_gradient_functions argument
  # and figure out if these needs to be registered.
  