Add dandi-publish to Docker Compose setup

[jwodder]

Closes #164.

[codecov]

Codecov Report

Merging #232 into master will increase coverage by 0.40%.
The diff coverage is 100.00%.

@@            Coverage Diff             @@
##           master     #232      +/-   ##
==========================================
+ Coverage   81.62%   82.03%   +0.40%     
==========================================
  Files          50       50              
  Lines        4168     4235      +67     
==========================================
+ Hits         3402     3474      +72     
+ Misses        766      761       -5     

Flag	Coverage Δ
#unittests	82.03% <100.00%> (+0.40%)	⬆️

Flags with carried forward coverage won't be shown. Click here to find out more.

Impacted Files	Coverage Δ
dandi/tests/fixtures.py	96.49% <100.00%> (+0.57%)	⬆️
dandi/support/tests/test_cache.py	97.93% <0.00%> (+4.23%)	⬆️

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update efdd6e2...2022f29. Read the comment docs.

[yarikoptic]

Great! now we should be able to test /publish and thus downloads of versioned datasets etc. Thank you @jwodder !