Run Session context/state

[readicculus]

Develop ability for a run to be contained within a 'session'. A 'session' has state and will allow for:

• Serializable context
  • Make context serializable so that a run can be reproduced
    • Include model/pipeline info
    • Configuration parameters used
    • Input image lists
    • Saving checkpoints/allow to resume a partially completed session/task
• Session has a working directory for all resulting artifacts
• Logging
  • Kwiver/viame logs
  • Make it clear to a user when a single dataset is complete