Response.protocol attribute

[elacuesta]

Motivated by #4769 and #4770

$ scrapy shell https://example.org
(...)
>>> response.protocol
'HTTP/1.1'
>>> 

[codecov]

Codecov Report

Merging #4878 (2405df4) into master (c20b342) will decrease coverage by 0.02%.
The diff coverage is 80.00%.

@@            Coverage Diff             @@
##           master    #4878      +/-   ##
==========================================
- Coverage   87.86%   87.84%   -0.03%     
==========================================
  Files         160      160              
  Lines        9750     9762      +12     
  Branches     1439     1437       -2     
==========================================
+ Hits         8567     8575       +8     
- Misses        926      929       +3     
- Partials      257      258       +1     

Impacted Files	Coverage Δ
scrapy/core/downloader/handlers/http11.py	92.46% <60.00%> (-0.57%)	⬇️
scrapy/core/downloader/webclient.py	94.48% <100.00%> (ø)
scrapy/http/response/__init__.py	97.40% <100.00%> (+0.03%)	⬆️
scrapy/core/downloader/__init__.py	90.97% <0.00%> (-1.51%)	⬇️
scrapy/extensions/feedexport.py	95.32% <0.00%> (+0.10%)	⬆️

[kmike]

Nice feature 👍

[kmike]

👍 Thanks @elacuesta!
As @Gallaecio also checked it, I'll leave it to him to merge.