Text fields shouldn't have null=True. (#94)

apps/files/migrations/0005_auto_20180922_1717.py

@@ -0,0 +1,27 @@
+# -*- coding: utf-8 -*-
+# Generated by Django 1.11.15 on 2018-09-22 17:17
+from __future__ import unicode_literals
+
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('files', '0004_auto_20180530_0308'),
+    ]
+
+    operations = [
+        migrations.AlterField(
+            model_name='imagefile',
+            name='caption',
+            field=models.CharField(blank=True, default='', max_length=240, verbose_name='Image caption'),
+            preserve_default=False,
+        ),
+        migrations.AlterField(
+            model_name='imagefile',
+            name='credit',
+            field=models.CharField(blank=True, default='', max_length=240, verbose_name='Image credit'),
+            preserve_default=False,
+        ),
+    ]