Add sha256sum to Source model

Allow us to record a checksum for local sources (and potentially remote
ones if it is recorded in the recipe). This just adds the field, but
doesn't populate it.

Signed-off-by: Paul Eggleton <paul.eggleton@linux.intel.com>

layerindex/migrations/0034_source_sha256sum.py

@@ -0,0 +1,20 @@
+# -*- coding: utf-8 -*-
+# Generated by Django 1.11.16 on 2019-04-01 03:20
+from __future__ import unicode_literals
+
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('layerindex', '0032_patchdisposition'),
+    ]
+
+    operations = [
+        migrations.AddField(
+            model_name='source',
+            name='sha256sum',
+            field=models.CharField(blank=True, max_length=64),
+        ),
+    ]

layerindex/models.py

@@ -524,6 +524,7 @@ class Recipe(models.Model):
 class Source(models.Model):
     recipe = models.ForeignKey(Recipe)
     url = models.CharField(max_length=255)
+    sha256sum = models.CharField(max_length=64, blank=True)
 
     def web_url(self):
         def drop_dotgit(url):