Add new fields in ContainerBoxContainers
Add field ContainerBoxContainers in admin
generate migration containers add news fields in ContainerBoxContainers
Fix image not is blank true in Imaged class
remve opps contrib admin migrate, not used
Merge branch 'master' of github.com:opps/opps

* 'master' of github.com:opps/opps:
  bug fix bug container slugify, ref #211
  write models test
  make instructions more clear
  readme install opps instructions
Update make test, used coverage run