Adds a management command to rebuild MPTT models

- Important to do after importing records / fixtures!
- Otherwise very strange things might happen especially when you try to use the API...

tasks.py

@@ -129,6 +129,14 @@ def wait(c):
 
     manage(c, "wait_for_db")
 
+@task
+def rebuild(c):
+    """
+    Rebuild database models with MPTT structures
+    """
+
+    manage(c, "rebuild_models")
+
 @task
 def migrate(c):
     """
@@ -311,7 +319,7 @@ def export_records(c, filename='data.json'):
     print("Data export completed")
 
 
-@task(help={'filename': 'Input filename'})
+@task(help={'filename': 'Input filename'}, post=[rebuild])
 def import_records(c, filename='data.json'):
     """
     Import database records from a file
@@ -354,7 +362,7 @@ def import_records(c, filename='data.json'):
 
     print("Data import completed")
 
-@task
+@task(post=[rebuild])
 def import_fixtures(c):
     """
     Import fixture data into the database.