Disk Driver Vault Deletion Fix

JIRA: CBDEUCE-129

- Enhancement: Add check for blocks being stored by the disk storage driver
-- Return True if the vault does not exist or can be deleted
-- Return False if there is content in the vault or any kind of error occurs
Disk Driver Vault Deletion Fix

JIRA: CBDEUCE-129
- Enhancement: Updated the vault deletion end-point to return 204 if the vault was deleted or 412 if it was not
Disk Driver Vault Deletion Fix

JIRA: CBDEUCE-129
- Enhancement: Use the create_project_id() instead of a static version
- Enhancement: Added a tests for the vault deletion to ensure we don't delete a non-empty vault
Disk Driver Vault Deletion Fix

JIRA: CBDEUCE-129

- Pep8 fixes
Merge branch 'master' into bugfix_disk_driver_vault_deletion
Disk Driver Vault Deletion Fix

JIRA: CBDEUCE-129
- Updated comment to reflect what is really happening
Merge branch 'master' into bugfix_disk_driver_vault_deletion

Conflicts:
	deuce/controllers/vault.py
Disk Driver Vault Deletion Fix

JIRA: CBDEUCE-129
- More re-use
Merge branch 'master' into bugfix_disk_driver_vault_deletion
Merge pull request #64 from BenjamenMeyer/bugfix_disk_driver_vault_deletion

Bugfix disk driver vault deletion