Add rule to tox.ini to build sphinx docs

[johannaengland]

Closes #1083.

[codecov-commenter]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 79.83%. Comparing base (4cedd03) to head (152caf2).

Additional details and impacted files

@@           Coverage Diff           @@
##           master    #1107   +/-   ##
=======================================
  Coverage   79.83%   79.83%           
=======================================
  Files         145      145           
  Lines        5267     5267           
=======================================
  Hits         4205     4205           
  Misses       1062     1062           

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

[hmpf]

This does not work unless tox is run inside a virtualenv

[johannaengland]

This does not work unless tox is run inside a virtualenv

I can run it outside a virtualenv without any problems

[hmpf]

It works for me if I remove the PYTHONPATH-line.

[hmpf]

Also, I wonder if we ought to have a settings-file for cases like this, with lost of things hardcoded. "dev" does too much and "backend" demands certain settings as environment variables.

It seems to work using "base" though.

[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud