Change the range catalog query to be a textfield.

The catalog query field needs to be able to store more than 255 characters,
therefor it's being changed to a Django TextField field.

https://openedx.atlassian.net/browse/SOL-2101

ecommerce/extensions/offer/migrations/0007_auto_20161026_0856.py

+# -*- coding: utf-8 -*-
+from __future__ import unicode_literals
+
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('offer', '0006_auto_20161025_1446'),
+    ]
+
+    operations = [
+        migrations.AlterField(
+            model_name='range',
+            name='catalog_query',
+            field=models.TextField(null=True, blank=True),
+        ),
+    ]

ecommerce/extensions/offer/models.py

@@ -75,7 +75,7 @@ class Range(AbstractRange):
         'course_seat_types',
     ]
     catalog = models.ForeignKey('catalogue.Catalog', blank=True, null=True, related_name='ranges')
-    catalog_query = models.CharField(max_length=255, blank=True, null=True)
+    catalog_query = models.TextField(blank=True, null=True)
     course_seat_types = models.CharField(
         max_length=255,
         validators=[validate_credit_seat_type],

ecommerce/extensions/offer/tests/test_models.py

@@ -61,6 +61,20 @@ class RangeTests(CouponMixin, CourseCatalogTestMixin, CourseCatalogMockMixin, Te
         self.assertIn(self.product, self.range_with_catalog.all_products())
         self.assertEqual(len(self.range_with_catalog.all_products()), 1)
 
+    def test_large_query(self):
+        """Verify the range can store large queries."""
+        large_query = """
+            Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod
+            tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam,
+            quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo
+            consequat. Duis aute irure dolor in reprehenderit in voluptate velit esse
+            cillum dolore eu fugiat nulla pariatur. Excepteur sint occaecat cupidatat
+            non proident, sunt in culpa qui officia deserunt mollit anim id est laborum.
+        """
+        self.range.catalog_query = large_query
+        self.range.save()
+        self.assertEqual(self.range.catalog_query, large_query)
+
     @mock.patch('ecommerce.core.url_utils.get_current_request', mock.Mock(return_value=None))
     def test_run_catalog_query_no_request(self):
         """