Bug fixes

- Part creation form was setting a field as HiddenInput() rather than its widget
- Added 'comment' file to FileAttachment model

InvenTree/part/migrations/0014_partattachment_comment.py

@@ -0,0 +1,18 @@
+# Generated by Django 2.2 on 2019-04-30 23:34
+
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('part', '0013_auto_20190429_2229'),
+    ]
+
+    operations = [
+        migrations.AddField(
+            model_name='partattachment',
+            name='comment',
+            field=models.CharField(blank=True, help_text='Attachment description', max_length=100),
+        ),
+    ]