Django-minio-backend

**Core feature:** Support for multiple buckets

**NON-BACKWARD COMPATIBLE CHANGES:**
* Merge pull request 5 from guyeshet/master
* API has changed for `class MinioBackend(Storage)`
The `bucket_name` parameter must be provided.

Changes to `settings.py`:
* Removed parameter: MINIO_PRIVATE_BUCKET_NAME
* Removed parameter: MINIO_PUBLIC_BUCKET_NAME
* New parameter: MINIO_PRIVATE_BUCKETS
* New parameter: MINIO_PUBLIC_BUCKETS
* New parameter: MINIO_POLICY_HOOKS
* New parameter: MINIO_CONSISTENCY_CHECK_ON_START

Additional summary
* Merge pull request 5 from guyeshet/master
removed no_translations because it's deprecated in Django 2.2.8

* PoolManager changed to HTTPSConnectionPool
  * SSL validation disabled(cert_reqs='CERT_NONE',assert_hostname=False)

* path() raise error text updated
  * get_accessed_time now raise NotImplementedError
  * get_created_time now raise NotImplementedError