Django-nextflow

- Partial data upload will now optionally verify filesize matches expected.

- Data objects can now be created from upload objects blob by blob.
- `is_ready`field added to Data to denote those in process of being created.
- Models now have default ordering.
- Executions can now be manually created with very minimal information.
- Fixed missing MD5 hash for pipeline output files.
- Fixed issue with generating finished time when values were missing.

- Execution objects now have label and notes fields.
- Data objects now have label and notes fields.
- Added method to 'remove' data objects rather than delete them entirely.
- Data objects now have MD5 hash upon creation.

- Executions can now generate a graph representation of themselves.
- Data objects can now detect all their up/downstream data within an execution.

- Pipelines now have a `run_and_update` method, for constant Execution updating.
- Better Execution ID generation.

- Pipelines can now take execution inputs.
- Fixed method for detecting downstream data products.