Reformat API Path

[XunliYang]

Problem description

Reduced path depth from 3-4 levels to 2-3 levels

• RESTful resource hierarchy - slices contain devices, devices belong to slices
• Use HTTP methods - GET for retrieval, POST for creation, DELETE for removal

Resource-oriented URLs - paths represent resources, not actions

• Consistent naming - no verbs in URLs (removed "assign", "release", "get", "retrieve")
• Logical nesting - devices are sub-resources of slices where appropriate

Current Paths (with issues)

/slices/devices/assign # 3 levels deep
/slices/devices/release # 3 levels deep
/slices/devices/get/{sliceId} # 4 levels deep
/slices/devices/retrieve # 3 levels deep

Possible evolution

/slices/{sliceId}/devices:
post: # Assign device to slice
get: # Get devices assigned to slice

/slices/{sliceId}/release:
post: # Release device from slice (verb path, device in body)

/retrieve-slices:
post: # Retrieve slices by device (verb path, device in body)