plotly graphs show in GitHub.io but not readthedocs

[ramcdougal]

Graphs are visible and interactive here:

https://neuronsimulator.github.io/nrn/rxd-tutorials/Combining%20currents%20from%20mod%20files%20with%20rxd.html

but not on the corresponding readthedocs page:

https://nrn.readthedocs.io/en/latest/rxd-tutorials/Combining%20currents%20from%20mod%20files%20with%20rxd.html

They should work in both places.

[alexsavulescu]

No indication as to why that didn't get through on RTD:

[NbConvertApp] Converting notebook Combining currents from mod files with rxd.ipynb to html
[NbConvertApp] Executing notebook with kernel: python3
Warning: no DISPLAY environment variable.
--No graphics will be displayed.
[NbConvertApp] Writing 4326458 bytes to Combining currents from mod files with rxd.html

[alexsavulescu]

From page logs:

Uncaught TypeError: require.undef is not a function
    at Combining currents from mod files with rxd.html:14791
(anonymous) @ Combining currents from mod files with rxd.html:14791

theme.js:3 Uncaught Error: Cannot find module 'plotly'
    at c (theme.js:3)
    at Combining currents from mod files with rxd.html:14873

[alexsavulescu]

Looks related to : readthedocs/sphinx_rtd_theme#788

[alexsavulescu]

So the issue was RTD was superseding sphinx_rtd_theme. Fixed in RTD via readthedocs/readthedocs.org#8059