implement a `skip_config_creation` option in `get_user_info`

[sbillinge]

Problem

A user may want to user get_user_info but not want it to interrupt execution if it can't find a config file.b

Proposed solution

as a NON DEFAULT option allow them to override interrupt.

This occured to @sbillinge while he was tweaking the docs. He wrote the docs as if it were implemented. Here is what he wrote:

Getting user data with no config files and with no interruption of execution
----------------------------------------------------------------------------

If you would like get run ``get_user_data()`` but without execution interruption even if it cannot find
an input file, type

.. code-block:: python

    user_data = get_user_data(skip_config_creation=True)

But this needs to be implemented