Proxpi

*Changes since v1.0rc0*

Changes
* Use [Gunicorn](https://gunicorn.org/) for serving in Docker container

Improvements
* (Attempt to) log `proxpi` version on server start-up

*Changes since v0.1*

Features
* Add home page with index invalidation and link to index root
* Add environment variable `PROXPI_CACHE_DIR` to set file-cache directory

Improvements
* Reduced Docker image size
* Avoid requesting index by assuming package URL
* Use single request session for cache
* Protect file-cache eviction with a lock
* Remove smallest files first when evict from file-cache
* Convert user-assert into RuntimeError

Fixes
* Download-fail response not cached

bash

Features
* Cache configuration is logged (info level) on start-up
* Add CI-specific documentation in the README

Changes
* Extra index URLs and TTLs in environment variables `PROXPI_EXTRA_INDEX_URLS` and `PROXPI_EXTRA_INDEX_TTLS` are comma-separated instead of white-space separated
* Package file download (eg due to cache directory permissions, or to unauthorised request) will redirect client to download from original URL instead of crashing server

Improvements
* Jinja is required
* Cached files are saved using original filename

Fixes
* Docker image has `lxml` installed

Changes
* Main index environment variables have been renamed (dropped the `ROOT` part)

Improvements
* Files aren't downloaded at all if file-cache is disabled (ie max file cache size is 0)
* Passwords are masked in logged URLs