Adding a docstring for stormpath.resource.custom_data.
Re-ordering imports.
Reordering parent classes.
Whitespace.
Style.
Whitespace.
Adding docstring, reordering imports.
Updating Directory docstring.
Updating ordering / style for attributes.
Minor style changes.
Whitespace.
Reordering imports.
Updating broken documentation link.
Style change.
Re-ordering for style.
Updating Group.add_account() docstring slightly.
Minor style fix.
Minor style fix.
Reordering imports, adding docstring for GroupMembership.
Updating GroupMembership docstring.