Delete obsolete code

assets/migrations/0012_remove_asset_next_sched_maint.py

@@ -0,0 +1,17 @@
+# Generated by Django 3.0.3 on 2020-03-18 00:24
+
+from django.db import migrations
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('assets', '0011_auto_20200317_2006'),
+    ]
+
+    operations = [
+        migrations.RemoveField(
+            model_name='asset',
+            name='next_sched_maint',
+        ),
+    ]