fix: channel.json supporting subchannel, and generic channel.json on containers root
fix: support to recursive channeling
Merge branch 'master' into fix

* master:
  Added url field in ContainerBoxContainers
fix pep8, channel admin
opps/channels/admin.py:57:80: E501 line too long (91 > 79 characters)
opps/channels/admin.py:70:80: E501 line too long (85 > 79 characters)