* Upgrade cryptography to 3.4.6
* Fix comment with instructions for how to use hashin
* run tools/rebuild_certbot_constraints.py
* add deps for building cryptography in snaps
* Update cryptography build dependencies for docker
* Update sources for test farm tests
* Remove rust if it's installed for test farm tests
* source bootstrap script and call sudo as needed
* Create bootstrap script
* Delete a whole bunch of the bootstrap script
* modify test_tests to use new script
* put python version checking in back in
* add x
* call the venv creation from inside the bootstrap
* add targets back
* modify test_apache2 to use new format
* shouldn't need virtualenv on rhel
* readd targets
* Update test_sdists to use new script
* move setting up venv back out of script so it's not run with sudo
* take venv3.py call out of bootstrap in all scripts
* add additional python3-devel pkg name
* fix test_sdists
* enable additional rhel7 repos
* clean up code and comments
* Update tests and instructions to use auto_targets.yaml with test_leauto_upgrades.sh and test_letsencrypt_auto_certonly_standalone.sh
* only install python3-devel.x86_64 for rhel7
* Upgrade python version for debian in test_apache2.sh
* don't run test_tests or test_sdists on debian 9 or ubuntu 16.04
* Add 20.04 and 20.04 arm images to targets.yaml
* use pyenv to upgrade to python3.5
* remove arm64 instance because it's having auth trouble
* correct pyenv usage on ubuntu
* add arm64 target to targets.yaml
* replace debian 9 arm64 with ubuntu 20
* don't try to upgrade a perfectly good python version
* let's just add ubuntu20 to apache2_targets while we're here
* uncomment test_apache2
* move adding python3-devel.x86_64 to bootstrap_os_packages to avoid potential race condition
* no need to specify the arch once extra rhel7 repos enabled
* explicitly specify python3
* don't fail if we can't enable rhel7 extras
* capture python36-devel as well
