* Move version.py to tests/letstest since it's used by test_sdists.sh
* Delete unused components of certbot-auto
* Remove test_leauto_upgrades.sh and references to it
* Remove test_letsencrypt_auto_certonly_standalone.sh and references to it
* Remove outstanding references to certbot-auto
* Remove references to letsencrypt-auto
* find certbot in the correct directory
* delete letsencrypt-auto-source line from .isort.cfg since that directory no longer contains any python code
* remove (-auto) from certbot(-auto)
* delete line from test
* Improve style for version.py
