v0.22.0

Changed

• [server] Update client-go to v6.0.0 and bump minimum k8s version to 1.9
• [server] Use an explicit selector for the deploy spec
• [server] app create requires vhost when ingress is enabled
• Bump the default slugrunner version to v3.2.0
• Bump the default slugbuilder version to v3.4.0

Fixed

• [server] Return not implemented error when enabling ssl with ingress on aws