Add validator to part name

- Check for 'illegal' characters
- Mostly just as a test for validators!

InvenTree/part/migrations/0021_auto_20190510_2220.py

@@ -0,0 +1,19 @@
+# Generated by Django 2.2 on 2019-05-10 12:20
+
+import InvenTree.validators
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('part', '0020_auto_20190510_2022'),
+    ]
+
+    operations = [
+        migrations.AlterField(
+            model_name='part',
+            name='name',
+            field=models.CharField(help_text='Part name', max_length=100, validators=[InvenTree.validators.validate_part_name]),
+        ),
+    ]