Added multiple api servers in compose file. nginx load balancing

[radiantone]

Just issuing a PR so you can see what I did here. If you feel it's useful to have in main branch, then feel free to merge. If not, then decline it.

[radiantone]

Yes, I updated the config

  limit_req_zone $http_authorization_key zone=one:10m rate=40r/m;
  limit_conn_zone $http_authorization_key zone=addr:10m;

where $http_authorization_key = 'Authorization-Key' request header field

[codecov-commenter]

Codecov Report

Merging #81 (88e6022) into main (d9bfd64) will increase coverage by 0.04%.
The diff coverage is n/a.

@@            Coverage Diff             @@
##             main      #81      +/-   ##
==========================================
+ Coverage   65.25%   65.30%   +0.04%     
==========================================
  Files         146      150       +4     
  Lines        9021     9134     +113     
  Branches     1114     1135      +21     
==========================================
+ Hits         5887     5965      +78     
- Misses       2856     2886      +30     
- Partials      278      283       +5     

Impacted Files	Coverage Δ
balsam/server/routers/jobs.py	86.56% <0.00%> (-6.86%)	⬇️
balsam/schemas/session.py	93.75% <0.00%> (-6.25%)	⬇️
balsam/server/utils/paginator.py	94.44% <0.00%> (-5.56%)	⬇️
balsam/server/models/crud/transfers.py	72.22% <0.00%> (-3.19%)	⬇️
balsam/server/models/crud/sessions.py	92.17% <0.00%> (-2.38%)	⬇️
balsam/_api/manager.py	83.43% <0.00%> (-0.29%)	⬇️
balsam/server/routers/filters.py	87.09% <0.00%> (-0.23%)	⬇️
balsam/_api/models.py	94.57% <0.00%> (-0.12%)	⬇️
balsam/schemas/job.py	87.41% <0.00%> (-0.09%)	⬇️
balsam/site/job_source.py	92.24% <0.00%> (ø)
... and 19 more

---

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 d9bfd64...88e6022. Read the comment docs.