fixed and cleand up a lot of servings related stuff

cookbook/migrations/0093_auto_20201231_1236.py

@@ -0,0 +1,30 @@
+# Generated by Django 3.1.4 on 2020-12-31 11:36
+
+import datetime
+import django.core.validators
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('cookbook', '0092_recipe_servings'),
+    ]
+
+    operations = [
+        migrations.RenameField(
+            model_name='mealplan',
+            old_name='recipe_multiplier',
+            new_name='servings',
+        ),
+        migrations.AlterField(
+            model_name='invitelink',
+            name='valid_until',
+            field=models.DateField(default=datetime.date(2021, 1, 14)),
+        ),
+        migrations.AlterField(
+            model_name='unit',
+            name='name',
+            field=models.CharField(max_length=128, unique=True, validators=[django.core.validators.MinLengthValidator(1)]),
+        ),
+    ]