Pacifica-metadata

Changed
- QuickFix 244 Missed column renames by [dmlb2000](https://github.com/dmlb2000)

Changed
- Fix 240 Add Dataset model and relationships by [dmlb2000](https://github.com/dmlb2000)
- Fix 238 Rename UserGroup column by [dmlb2000](https://github.com/dmlb2000)
- Fix 236 Add Hashlist column operations by [dmlb2000](https://github.com/dmlb2000)

Changed
- Fix 233 Loosen where clause for users by [kauberry](https://github.com/kauberry)
- Fix 231 Update Docs by [dmlb2000](https://github.com/dmlb2000)

Changed
- Fix 223 Add Nice Status Url by [dmlb2000](https://github.com/dmlb2000)
- Fix 225 Add UUID check for JSON serialization [dmlb2000](https://github.com/dmlb2000)
- Fix user lookup clause in user queries endpoint [kauberry](https://github.com/kauberry)

Added
- Metadata model
- Dublin Core additions
- Files grouped by transactions
- Instruments, Analytical Tools, Projects and Users
- Arbitrary Relationships between above objects
- Arbitrary Key Value Pairs for Files and Transactions
- Extended REST API for introspection of objects
- Endpoints for Uploading Metadata
- Notifications for changes in the system
- Object update/create/delete
- Ingest event
- DOI related events
- Metadata Model Upgrade Process
- ReadtheDocs supported Sphinx docs
- REST API for sending and recieving data
- PUT - Create an Object
- POST - Update an Object
- GET - Get an Object
- DELETE - Delete an Object

Changed