Updated base image from python:2-alpine to python:2-alpine3.7. Python:2-alpine internally utilises alpine version 3.4 which end-of-life date is the first of May 2018.
When I try to build container I see in logs
```
debconf: unable to initialize frontend: Dialog
debconf: (TERM is not set, so the dialog frontend is not usable.)
debconf: falling back to frontend: Readline
debconf: unable to initialize frontend: Readline
debconf: (This frontend requires a controlling tty.)
debconf: falling back to frontend: Teletype
```
`DEBIAN_FRONTEND=noninteractive` fixed this warning
Remove the old bootstrap scripts, which have been subsumed into letsencrypt-auto-source/pieces/bootstrappers. They no longer need to be dispatched among manually: everyone can just run letsencrypt-auto --os-packages-only, regardless of OS.
Make the root-level le-auto a symlink to the canonical version. It should thus still work for people running le-auto from a git checkout.
le latest e1f2e8ce3a0e 14 minutes ago 780.2 MB
vs
le latest d3276dd3976c About a minute ago 393.6 MB
where:
buildpack-deps jessie ecff3a5a9760 12 days ago 677.4 MB
debian jessie 41b730702607 13 days ago 125.1 MB
Changes:
- uses debian:jessie as base image (more lightweight)
- .dockerignore .git/.tox to speed up build process considerably
- more caching-aware Dockerfile
- copy current directory instead of git cloning the repo inside the container
- /etc/letsencrypt and /var/lib/letsencrypt volumes;
no need for "if os.environ.get" hack
bootstrap script for debian had to be adjusted, as lsb_release is not
present in debian:jessie image.
