v0.27

• [BUGFIX] Fix parsing error with silence end date
• [BUGFIX] Fix webhook POST data
• [CHANGE] Update Celery version for bug fix
• [IMPROVEMENT] Cleanup some page headers to make navigation easier
• [IMPROVEMENT] Simple proxy page for /graph view
• [IMPROVEMENT] Speed up services page with prefetch_related_objects
• [IMPROVEMENT] Support entering comma separated list of hosts
• [IMPROVEMENT] Support for disabling a shard (disables adding new services)
• [IMPROVEMENT] Use css grid to improve readability of long pages
• [IMPROVEMENT] Warn if parent rull is missing macro