Deepssm command

[akenmorris]

This PR adds the deepssm command to the shapeworks executable:

Usage: deepssm [args]...

run deepssm steps

Options:
  -h, --help            show this help message and exit
  --name=STRING         Path to input project file (xlsx or swproj).
  --prep=CHOICE         Preparation step to run (choose from 'all',
                        'groom_training', 'optimize_training',
                        'optimize_validation', 'groom_images')
  --augment             Run data augmentation
  --train               Run training
  --test                Run testing
  --all                 Run all steps

This replicates the implementation that ShapeWorksStudio uses, but in a CLI form. The Studio implementation was refactored out and placed in a new library called "Application" for application-specific classes that can be re-used by multiple modules.

This will make it easier to add automated tests for the DeepSSM module of ShapeWorksStudio.