automodapi overlapped text

I'm using the current `master` branch of the astropy package template to build docs in my package [`pyoof`](https://github.com/tcassanelli/pyoof). Everything works fine in the offline version, but when the online version builds there is text that overlaps in the API `automodapi `.

**Offline**

**Online**

I tried several options from the [`sphinx-automodapi`](https://sphinx-automodapi.readthedocs.io/en/latest/automodapi.html) , e.g.
```
.. automodapi:: pyoof
:include-all-objects:
```
but again, it builds fine offline (`python setup.py build_docs`) but online it does not.
Perhaps it is something else that I need to fix this problem? maybe in `conf.py` file?
My package `pyoof` docs are [here](https://github.com/tcassanelli/pyoof/tree/master/docs) and the they are hosted in [_readthedocs_](https://readthedocs.org/projects/pyoof/).

Start with the pyoof docs linked in the issue, especially docs/conf.py and the .. automodapi:: pyoof directive. Reproduce both python setup.py build_docs and the ReadTheDocs build, then compare the rendered API page and the sphinx-automodapi configuration. Done means the automodapi text no longer overlaps in the online build while remaining correct offline.

Written by the indexing model from the issue text.