fixed and cleand up a lot of servings related stuff

cookbook/migrations/0094_auto_20201231_1238.py

@@ -0,0 +1,18 @@
+# Generated by Django 3.1.4 on 2020-12-31 11:38
+
+from django.db import migrations
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('cookbook', '0093_auto_20201231_1236'),
+    ]
+
+    operations = [
+        migrations.RenameField(
+            model_name='shoppinglistrecipe',
+            old_name='multiplier',
+            new_name='servings',
+        ),
+    ]