Move SupplierPart and SupplierPriceBreak to the 'Company' app

- https://docs.djangoproject.com/en/2.2/ref/models/options/#django.db.models.Options.db_table
- https://stackoverflow.com/questions/3519143/django-how-to-specify-a-database-for-a-model
- And others, presumably

InvenTree/company/migrations/0007_supplierpart_supplierpricebreak.py

@@ -0,0 +1,52 @@
+# Generated by Django 2.2 on 2019-05-18 07:59
+
+import django.core.validators
+from django.db import migrations, models
+import django.db.models.deletion
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('part', '0032_auto_20190518_1759'),
+        ('company', '0006_auto_20190508_2332'),
+    ]
+
+    operations = [
+        migrations.CreateModel(
+            name='SupplierPart',
+            fields=[
+                ('id', models.AutoField(auto_created=True, primary_key=True, serialize=False, verbose_name='ID')),
+                ('SKU', models.CharField(help_text='Supplier stock keeping unit', max_length=100)),
+                ('manufacturer', models.CharField(blank=True, help_text='Manufacturer', max_length=100)),
+                ('MPN', models.CharField(blank=True, help_text='Manufacturer part number', max_length=100)),
+                ('URL', models.URLField(blank=True, help_text='URL for external supplier part link')),
+                ('description', models.CharField(blank=True, help_text='Supplier part description', max_length=250)),
+                ('note', models.CharField(blank=True, help_text='Notes', max_length=100)),
+                ('base_cost', models.DecimalField(decimal_places=3, default=0, help_text='Minimum charge (e.g. stocking fee)', max_digits=10, validators=[django.core.validators.MinValueValidator(0)])),
+                ('packaging', models.CharField(blank=True, help_text='Part packaging', max_length=50)),
+                ('multiple', models.PositiveIntegerField(default=1, help_text='Order multiple', validators=[django.core.validators.MinValueValidator(1)])),
+                ('minimum', models.PositiveIntegerField(default=1, help_text='Minimum order quantity (MOQ)', validators=[django.core.validators.MinValueValidator(1)])),
+                ('lead_time', models.DurationField(blank=True, null=True)),
+                ('part', models.ForeignKey(help_text='Select part', limit_choices_to={'purchaseable': True}, on_delete=django.db.models.deletion.CASCADE, related_name='supplier_parts', to='part.Part')),
+                ('supplier', models.ForeignKey(help_text='Select supplier', limit_choices_to={'is_supplier': True}, on_delete=django.db.models.deletion.CASCADE, related_name='parts', to='company.Company')),
+            ],
+            options={
+                'db_table': 'part_supplierpart',
+                'unique_together': {('part', 'supplier', 'SKU')},
+            },
+        ),
+        migrations.CreateModel(
+            name='SupplierPriceBreak',
+            fields=[
+                ('id', models.AutoField(auto_created=True, primary_key=True, serialize=False, verbose_name='ID')),
+                ('quantity', models.PositiveIntegerField(default=1, validators=[django.core.validators.MinValueValidator(1)])),
+                ('cost', models.DecimalField(decimal_places=3, max_digits=10, validators=[django.core.validators.MinValueValidator(0)])),
+                ('part', models.ForeignKey(on_delete=django.db.models.deletion.CASCADE, related_name='pricebreaks', to='company.SupplierPart')),
+            ],
+            options={
+                'db_table': 'part_supplierpricebreak',
+                'unique_together': {('part', 'quantity')},
+            },
+        ),
+    ]