new_contents: # Generated by Django 2.2.13 on 2020-08-14 12:37
  
  from django.db import migrations, models
  import django.db.models.deletion
  
  
  class Migration(migrations.Migration):
  
      dependencies = [
          ("observations", "0008_use_explicit_base_manager_name"),
      ]
  
      operations = [
          migrations.AlterField(
              model_name="observation",
              name="unit",
              field=models.ForeignKey(
                  help_text="The unit the observation is about",
                  on_delete=django.db.models.deletion.CASCADE,
                  related_name="observation_history",
                  to="services.Unit",
              ),
          ),
      ]
  
subject: Add missing migration