fix(celery-beat): don't use pidfile; custom scheduledb path
chore(readme): updated 'fig' section
chore(fig): added missing env vars
fix(ingest): make sure we ingest content as str not bytes

this will prevent errors with replacement rules which don't work
on bytes content being unicode

SD-703 SD-1199
Merge pull request #422 from actionless/celery-in-container

fix(celery-beat): don't use pidfile; custom scheduledb path
Merge pull request #426 from petrjasek/master

fix(ingest): make sure we ingest content as str not bytes
fix(celery): use crontab to schedule gc tasks

this should prevent some initial load when beat is started
because it schedules all tasks right away