bug fixes for v1.2

v1.2.3

patch for v1.2

Some fixes for registry

Patch:

1. Fixed the hard coded registry used to push and pull challenge images
2. Used more robust logic to define a registry object
3. Fixed HostSNI rule for web challenges
4. Modified private registry logic in deploy job

isolet cli v1.1.0

Added support for custom dynamic challenge deployment.yaml

isolet cli v1.0.0

This release includes commands like list, load, deploy and undeploy for challenges.
Next major release will include commands to manage events.