WIP workflows: Holding Pen authorization

WIP for *basic* authorization in Holding Pen (relying on user being connected to "viewholdingpen" authorization).

* Adds basic "viewholdingpen" authorization to access the Holding Pen.
* Fixes PEP8 issues in local_config.py.

RFC on how to take authorization in Holding Pen to the next level is upcoming.

@kaplun 

You can use it this way without importing it in `__init__`.
```python
from .acl import viewholdingpen
...
@permission_required(viewholdingpen.name)
...
```

--
in the future it would be nice to do something like `@viewholdingpen.required` or `@viewcol.required(name="Thesis")`.