Autodoc doesn't build properly on readthedocs

[jank324]

See title.

It does build correctly locally. The following lines from the build output might be interesting:

WARNING: autodoc: failed to import module 'accelerator'; the following exception was raised:
No module named 'matplotlib'
WARNING: autodoc: failed to import module 'particles'; the following exception was raised:
No module named 'numpy'
WARNING: autodoc: failed to import module 'track_methods'; the following exception was raised:
No module named 'numpy'
WARNING: autodoc: failed to import module 'utils'; the following exception was raised:
No module named 'numpy'