Delete canary feature

[duanhongyi]

Currently, it supports multiple procfiles and different images, so custom services and HTTPRoutes can be used.

See: #48

Canary is no longer necessary, so we plan to remove this feature in the future.

Involving the following projects:

• https://github.com/drycc/controller
• https://github.com/drycc/controller-sdk-go
• https://github.com/drycc/workflow-cli

[duanhongyi]

complete