Fix credit requirement "criteria" name

The CreditRequirement "configuration" field was renamed in Django
code without updating the migration.  This commit adds a second
migration to delete the incorrect field and add a new field.
The credit feature is currently disabled in production, so
the model isn't currently used by application code.

openedx/core/djangoapps/credit/migrations/0002_rename_credit_requirement_criteria_field.py

+# -*- coding: utf-8 -*-
+from south.utils import datetime_utils as datetime
+from south.db import db
+from south.v2 import SchemaMigration
+from django.db import models
+
+
+class Migration(SchemaMigration):
+
+    def forwards(self, orm):
+        # Deleting field 'CreditRequirement.configuration'
+        db.delete_column('credit_creditrequirement', 'configuration')
+
+        # Adding field 'CreditRequirement.criteria'
+        db.add_column('credit_creditrequirement', 'criteria',
+                      self.gf('jsonfield.fields.JSONField')(default=''),
+                      keep_default=False)
+
+
+    def backwards(self, orm):
+        # Adding field 'CreditRequirement.configuration'
+        db.add_column('credit_creditrequirement', 'configuration',
+                      self.gf('jsonfield.fields.JSONField')(default=''),
+                      keep_default=False)
+
+        # Deleting field 'CreditRequirement.criteria'
+        db.delete_column('credit_creditrequirement', 'criteria')
+
+
+    models = {
+        'credit.creditcourse': {
+            'Meta': {'object_name': 'CreditCourse'},
+            'course_key': ('xmodule_django.models.CourseKeyField', [], {'unique': 'True', 'max_length': '255', 'db_index': 'True'}),
+            'enabled': ('django.db.models.fields.BooleanField', [], {'default': 'False'}),
+            'id': ('django.db.models.fields.AutoField', [], {'primary_key': 'True'})
+        },
+        'credit.crediteligibility': {
+            'Meta': {'unique_together': "(('username', 'course'),)", 'object_name': 'CreditEligibility'},
+            'course': ('django.db.models.fields.related.ForeignKey', [], {'related_name': "'eligibilities'", 'to': "orm['credit.CreditCourse']"}),
+            'created': ('model_utils.fields.AutoCreatedField', [], {'default': 'datetime.datetime.now'}),
+            'id': ('django.db.models.fields.AutoField', [], {'primary_key': 'True'}),
+            'modified': ('model_utils.fields.AutoLastModifiedField', [], {'default': 'datetime.datetime.now'}),
+            'provider': ('django.db.models.fields.related.ForeignKey', [], {'related_name': "'eligibilities'", 'to': "orm['credit.CreditProvider']"}),
+            'username': ('django.db.models.fields.CharField', [], {'max_length': '255', 'db_index': 'True'})
+        },
+        'credit.creditprovider': {
+            'Meta': {'object_name': 'CreditProvider'},
+            'created': ('model_utils.fields.AutoCreatedField', [], {'default': 'datetime.datetime.now'}),
+            'display_name': ('django.db.models.fields.CharField', [], {'max_length': '255'}),
+            'id': ('django.db.models.fields.AutoField', [], {'primary_key': 'True'}),
+            'modified': ('model_utils.fields.AutoLastModifiedField', [], {'default': 'datetime.datetime.now'}),
+            'provider_id': ('django.db.models.fields.CharField', [], {'unique': 'True', 'max_length': '255', 'db_index': 'True'})
+        },
+        'credit.creditrequirement': {
+            'Meta': {'unique_together': "(('namespace', 'name', 'course'),)", 'object_name': 'CreditRequirement'},
+            'active': ('django.db.models.fields.BooleanField', [], {'default': 'True'}),
+            'course': ('django.db.models.fields.related.ForeignKey', [], {'related_name': "'credit_requirements'", 'to': "orm['credit.CreditCourse']"}),
+            'created': ('model_utils.fields.AutoCreatedField', [], {'default': 'datetime.datetime.now'}),
+            'criteria': ('jsonfield.fields.JSONField', [], {}),
+            'id': ('django.db.models.fields.AutoField', [], {'primary_key': 'True'}),
+            'modified': ('model_utils.fields.AutoLastModifiedField', [], {'default': 'datetime.datetime.now'}),
+            'name': ('django.db.models.fields.CharField', [], {'max_length': '255'}),
+            'namespace': ('django.db.models.fields.CharField', [], {'max_length': '255'})
+        },
+        'credit.creditrequirementstatus': {
+            'Meta': {'object_name': 'CreditRequirementStatus'},
+            'created': ('model_utils.fields.AutoCreatedField', [], {'default': 'datetime.datetime.now'}),
+            'id': ('django.db.models.fields.AutoField', [], {'primary_key': 'True'}),
+            'modified': ('model_utils.fields.AutoLastModifiedField', [], {'default': 'datetime.datetime.now'}),
+            'requirement': ('django.db.models.fields.related.ForeignKey', [], {'related_name': "'statuses'", 'to': "orm['credit.CreditRequirement']"}),
+            'status': ('django.db.models.fields.CharField', [], {'max_length': '32'}),
+            'username': ('django.db.models.fields.CharField', [], {'max_length': '255', 'db_index': 'True'})
+        }
+    }
+
+    complete_apps = ['credit']
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