Rename 3 remaining instances of slave to worker

[ibrahima]

Just noticed this when I was browsing the documentation.

[ibrahima]

Actually, there's probably a couple more that should be changed:

https://github.com/locustio/locust/search?q=slave&unscoped_q=slave

locust/locust/runners.py

Line 512 in bd198ac

logger.info("Reset connection to slave")

locust/locust/test/test_runners.py

Line 359 in cd08d0e

# check that slave nodes have started locusts

I think the other instances are places where the old options need to be handled with a deprecation warning.

[codecov]

Codecov Report

Merging #1400 into master will decrease coverage by 0.08%.
The diff coverage is 0.00%.

@@            Coverage Diff             @@
##           master    #1400      +/-   ##
==========================================
- Coverage   81.19%   81.11%   -0.09%     
==========================================
  Files          26       26              
  Lines        2335     2335              
  Branches      361      361              
==========================================
- Hits         1896     1894       -2     
- Misses        347      348       +1     
- Partials       92       93       +1     

Impacted Files	Coverage Δ
locust/runners.py	80.83% <0.00%> (ø)
locust/user/task.py	96.17% <0.00%> (-1.10%)	⬇️

---

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 55a350d...d22a03f. Read the comment docs.

[cyberw]

Nice, thanks!