v0.20.30

Changelog

• Improvement of UI
• Improvement of Agent stability
• Support crontab task for flow
• Support multiple docker containers
• Introduce docker/dockers YAML section on flow level
• Introduce android secret type to config android certificate
• New android flow template

Docker images

## core
docker pull flowci/core:latest
docker pull flowci/core:0.20.30

## web
docker pull flowci/web:latest
docker pull flowci/web:0.20.30

## agent
docker pull flowci/agent:latest
docker pull flowci/agent:0.20.30