1.26.18
[1.26.x] Add alternate 'dark mode' banner to documentation
Add deprecation warnings for pyOpenSSL and the [secure] extra
Make Travis CI fail if docs have warnings or errors
[1.26] Update docs for re-using HTTP connections after streaming
Backport publish workflow and process to 1.26.x
Adds changing branches for installing from git docs for 1.26.x
Importing Sphinx docs.
[1.26] Configure OS for RTD to fix building docs
[1.26] Recommend GitHub Sponsors instead of Open Collective
Document disabling certificate verification via cert_reqs='CERT_NONE'
[1.26] Fix compatible Python versions in v2-roadmap.rst (#2979)