implement SchemaEditor.create/delete_model()

Author: timgraham

.github/workflows/test-python.yml

@@ -110,6 +110,7 @@ jobs:
           ordering
           or_lookups
           queries
+          schema.tests.SchemaTests.test_creation_deletion
           select_related
           select_related_onetoone
           select_related_regress

django_mongodb/schema.py

@@ -3,10 +3,10 @@
 
 class DatabaseSchemaEditor(BaseDatabaseSchemaEditor):
     def create_model(self, model):
-        pass
+        self.connection.database.create_collection(model._meta.db_table)
 
     def delete_model(self, model):
-        pass
+        self.connection.database[model._meta.db_table].drop()
 
     def add_field(self, model, field):
         pass