WIP: Resolve "Add more management commands"

Closes #8

aleksis/apps/ldap/management/commands/import_user_by_name.py

+from django.core.management.base import BaseCommand
+
+from ...util.ldap_sync import import_user_by_username
+
+
+class Command(BaseCommand):
+    def add_arguments(self, parser):
+        parser.add_argument("username", type=str)
+
+    def handle(self, *args, **options):
+        username = options["username"]
+        import_user_by_username(username)