Add "is_manufacturer" field to company model

(cherry picked from commit fd45db9e22)

InvenTree/company/migrations/0015_company_is_manufacturer.py

@@ -0,0 +1,18 @@
+# Generated by Django 2.2.10 on 2020-04-12 23:21
+
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('company', '0014_auto_20200407_0116'),
+    ]
+
+    operations = [
+        migrations.AddField(
+            model_name='company',
+            name='is_manufacturer',
+            field=models.BooleanField(default=True, help_text='Does this company manufacture parts?'),
+        ),
+    ]