State Save + Restore State from Config + Redis State + Scope Fix 0.5.0 (#78)

* save state work:
- support interrupting and saving crawl
- support loading crawl state (frontier queue, pending, done) from YAML
- support scope check when loading to apply new scoping rules when restarting crawl
- failed urls added to done as failed, can be retried if crawl is stopped and restarted
- save state to crawls/crawl-<ts>-<id>.yaml when interrupted
- --saveState option controls when crawl state is saved, default to partial/when interrupted, also always, never.
- support in-memory or redis based crawl state, using fork of puppeteer-cluster
- --redisStore used to enable redis-based state



* signals/crawl interruption:
- crawl state set to drain/not provide any more urls to crawl
- graceful stop of crawl in response to sigint/sigterm
- initial sigint/sigterm waits for graceful end of current pages, second terminates immediately
- initial sigabrt followed by sigterm terminates immediately
- puppeteer disable handleSIGTERM, handleSIGHUP, handleSIGINT

* redis state support:
- use lua scripts for atomic move from queue -> pending, and pending -> done
- pending key expiry set to page timeout
- add numPending() and numSeen() to support better puppeteer-cluster semantics for early termination
- drainMax returns the numPending() + numSeen() to work with cluster stats

* arg improvements:
- add --crawlId param, also settable via CRAWL_ID env var, defaulting to os.hostname() (used for redis key and crawl state file)
- support setting cmdline args via env var CRAWL_ARGS
- use 'choices' in args when possible

* build update:
- switch base browser image to new webrecorder/browsertrix-browser-base, simple image with .deb files only for amd64 and arm64 builds
- use setuptools<58.0

* misc crawl/scoping rule fixes:
- scoping rules fix when external is used with scopeType
state:
- limit: ensure no urls, including initial seeds, are added past the limit
- signals: fix immediate shutdown on second signal
- tests: add scope test for default scope + excludes

*  py-wacz update
- add 'seed': true to pages that are seeds for optimized wacz creation, keeping non-seeds separate (supported via wacz 0.3.2)
- pywb: use latest pywb branch for improved twitter video capture

* update to latest browsertrix-behaviors

* fix setuptools dependency #88

* update README for 0.5.0 beta

requirements.txt

@@ -1,3 +1,4 @@
-pywb>=2.6.0
+#pywb>=2.6.0
+git+https://github.com/webrecorder/pywb@twitter-rw
 uwsgi
-wacz>=0.3.1
+wacz>=0.3.2