Bugfixes

• Fixed and issue with empty containers key in package.yaml

New

• added new flag --hub for the following commands
  • sina push
  • sina push
  • sina search
  • sina install
  • sina update
  • sina delete
  • sina pull
• added case-sensitive view in sina search
• optimized image handling in SINA packages

Removed

• removed flag --public for following commands
  • sina push
  • sina push
  • sina search
  • sina install
  • sina update
  • sina delete
  • sina pull
• removed following funtionalities for non-logged in user from public hub.
  • sina pull
  • sina install
  • sina update
  • sina delete
  • sina build