prompt: You will be provided with a partial code base and an issue statement explaining a problem to resolve.
  <issue>
  Django 2.1 upgrade
  https://docs.djangoproject.com/en/2.1/releases/2.1/
  
  There is a guide for upgrading: https://docs.djangoproject.com/en/2.1/howto/upgrade-version/
  
  Basically
  * Read the release notes
  * update dependencies
  * run tests with `python -Wa` and solve deprecation warnings
  * put the new django into the requirements
  * run tests, fix failures if any
  * run tests with `python -Wa` and solve deprecation warnings again
  * if there was any new feature in the release notes that might help us, use it
  
  also, we need to check the installed python version on production, django 2.1 supports python 3.5 and newer.
  
  </issue>
  <code>
  [start of evap/evaluation/migrations/0062_replace_textanswer_id_with_uuid.py]
  1 # Generated by Django 1.11.3 on 2017-07-03 18:31
  2 
  3 from django.db import migrations, models
  4 import uuid
  5 
  6 
  7 def fill_textanswer_uuid(apps, schema_editor):
  8     db_alias = schema_editor.connection.alias
  9     TextAnswer = apps.get_model('evaluation', 'TextAnswer')
  10     for obj in TextAnswer.objects.using(db_alias).all():
  11         obj.uuid = uuid.uuid4()
  12         obj.save()
  13 
  14 
  15 class Migration(migrations.Migration):
  16 
  17     dependencies = [
  18         ('evaluation', '0061_editor_review_reminder_template'),
  19     ]
  20 
  21     # Based on
  22     # https://gist.github.com/smcoll/8bb867dc631433c01fd0
  23 
  24     operations = [
  25         migrations.AddField(
  26             model_name='textanswer',
  27             name='uuid',
  28             field=models.UUIDField(null=True),
  29         ),
  30         migrations.RunPython(fill_textanswer_uuid, migrations.RunPython.noop),
  31         migrations.AlterField(
  32             model_name='textanswer',
  33             name='uuid',
  34             field=models.UUIDField(primary_key=False, default=uuid.uuid4, serialize=False, editable=False),
  35         ),
  36         # rename the old id field before deleting it at the end of the
  37         # migration for compatibility with the sqlite driver
  38         migrations.RenameField(
  39             model_name='textanswer',
  40             old_name='id',
  41             new_name='old_id'
  42         ),
  43         migrations.RenameField(
  44             model_name='textanswer',
  45             old_name='uuid',
  46             new_name='id'
  47         ),
  48         migrations.AlterField(
  49             model_name='textanswer',
  50             name='id',
  51             field=models.UUIDField(primary_key=True, default=uuid.uuid4, serialize=False, editable=False),
  52         ),
  53         migrations.AlterModelOptions(
  54             name='textanswer',
  55             options={'ordering': ['id'], 'verbose_name': 'text answer', 'verbose_name_plural': 'text answers'},
  56         ),
  57         migrations.RemoveField(model_name='textanswer', name='old_id'),
  58     ]
  59
  [end of evap/evaluation/migrations/0062_replace_textanswer_id_with_uuid.py]
  </code>
  
  I need you to solve this issue by generating a single patch file that I can apply directly to this repository using git apply. Please respond with a single patch file in the following format.
  <patch>
  diff --git a/file.py b/file.py
  --- a/file.py
  +++ b/file.py
  @@ -1,27 +1,35 @@
   def euclidean(a, b):
  -    while b:
  -        a, b = b, a % b
  -    return a
  +    if b == 0:
  +        return a
  +    return euclidean(b, a % b)
   
   
   def bresenham(x0, y0, x1, y1):
       points = []
       dx = abs(x1 - x0)
       dy = abs(y1 - y0)
  -    sx = 1 if x0 < x1 else -1
  -    sy = 1 if y0 < y1 else -1
  -    err = dx - dy
  +    x, y = x0, y0
  +    sx = -1 if x0 > x1 else 1
  +    sy = -1 if y0 > y1 else 1
   
  -    while True:
  -        points.append((x0, y0))
  -        if x0 == x1 and y0 == y1:
  -            break
  -        e2 = 2 * err
  -        if e2 > -dy:
  -            err -= dy
  -            x0 += sx
  -        if e2 < dx:
  -            err += dx
  -            y0 += sy
  +    if dx > dy:
  +        err = dx / 2.0
  +        while x != x1:
  +            points.append((x, y))
  +            err -= dy
  +            if err < 0:
  +                y += sy
  +                err += dx
  +            x += sx
  +    else:
  +        err = dy / 2.0
  +        while y != y1:
  +            points.append((x, y))
  +            err -= dx
  +            if err < 0:
  +                x += sx
  +                err += dy
  +            y += sy
  +
  +    points.append((x, y))
       return points
  
  </patch>
golden_diff: diff --git a/evap/evaluation/migrations/0062_replace_textanswer_id_with_uuid.py b/evap/evaluation/migrations/0062_replace_textanswer_id_with_uuid.py
  --- a/evap/evaluation/migrations/0062_replace_textanswer_id_with_uuid.py
  +++ b/evap/evaluation/migrations/0062_replace_textanswer_id_with_uuid.py
  @@ -33,13 +33,12 @@
               name='uuid',
               field=models.UUIDField(primary_key=False, default=uuid.uuid4, serialize=False, editable=False),
           ),
  -        # rename the old id field before deleting it at the end of the
  -        # migration for compatibility with the sqlite driver
  -        migrations.RenameField(
  -            model_name='textanswer',
  -            old_name='id',
  -            new_name='old_id'
  -        ),
  +        # this causes trouble with sqlite. We have two open bug reports with django for this, see
  +        # https://code.djangoproject.com/ticket/29790 and https://code.djangoproject.com/ticket/28541
  +        # We can not get this to work with sqlite and postgres right now and we want django2.1, we only
  +        # support postgres here. For sqlite, you need to rename the field here and move the RemoveField to
  +        # the end.
  +        migrations.RemoveField(model_name='textanswer', name='id'),
           migrations.RenameField(
               model_name='textanswer',
               old_name='uuid',
  @@ -54,5 +53,4 @@
               name='textanswer',
               options={'ordering': ['id'], 'verbose_name': 'text answer', 'verbose_name_plural': 'text answers'},
           ),
  -        migrations.RemoveField(model_name='textanswer', name='old_id'),
       ]
  
verification_info: {"golden_diff": "diff --git a/evap/evaluation/migrations/0062_replace_textanswer_id_with_uuid.py b/evap/evaluation/migrations/0062_replace_textanswer_id_with_uuid.py\n--- a/evap/evaluation/migrations/0062_replace_textanswer_id_with_uuid.py\n+++ b/evap/evaluation/migrations/0062_replace_textanswer_id_with_uuid.py\n@@ -33,13 +33,12 @@\n             name='uuid',\n             field=models.UUIDField(primary_key=False, default=uuid.uuid4, serialize=False, editable=False),\n         ),\n-        # rename the old id field before deleting it at the end of the\n-        # migration for compatibility with the sqlite driver\n-        migrations.RenameField(\n-            model_name='textanswer',\n-            old_name='id',\n-            new_name='old_id'\n-        ),\n+        # this causes trouble with sqlite. We have two open bug reports with django for this, see\n+        # https://code.djangoproject.com/ticket/29790 and https://code.djangoproject.com/ticket/28541\n+        # We can not get this to work with sqlite and postgres right now and we want django2.1, we only\n+        # support postgres here. For sqlite, you need to rename the field here and move the RemoveField to\n+        # the end.\n+        migrations.RemoveField(model_name='textanswer', name='id'),\n         migrations.RenameField(\n             model_name='textanswer',\n             old_name='uuid',\n@@ -54,5 +53,4 @@\n             name='textanswer',\n             options={'ordering': ['id'], 'verbose_name': 'text answer', 'verbose_name_plural': 'text answers'},\n         ),\n-        migrations.RemoveField(model_name='textanswer', name='old_id'),\n     ]\n", "issue": "Django 2.1 upgrade\nhttps://docs.djangoproject.com/en/2.1/releases/2.1/\r\n\r\nThere is a guide for upgrading: https://docs.djangoproject.com/en/2.1/howto/upgrade-version/\r\n\r\nBasically\r\n* Read the release notes\r\n* update dependencies\r\n* run tests with `python -Wa` and solve deprecation warnings\r\n* put the new django into the requirements\r\n* run tests, fix failures if any\r\n* run tests with `python -Wa` and solve deprecation warnings again\r\n* if there was any new feature in the release notes that might help us, use it\r\n\r\nalso, we need to check the installed python version on production, django 2.1 supports python 3.5 and newer.\n", "before_files": [{"content": "# Generated by Django 1.11.3 on 2017-07-03 18:31\n\nfrom django.db import migrations, models\nimport uuid\n\n\ndef fill_textanswer_uuid(apps, schema_editor):\n    db_alias = schema_editor.connection.alias\n    TextAnswer = apps.get_model('evaluation', 'TextAnswer')\n    for obj in TextAnswer.objects.using(db_alias).all():\n        obj.uuid = uuid.uuid4()\n        obj.save()\n\n\nclass Migration(migrations.Migration):\n\n    dependencies = [\n        ('evaluation', '0061_editor_review_reminder_template'),\n    ]\n\n    # Based on\n    # https://gist.github.com/smcoll/8bb867dc631433c01fd0\n\n    operations = [\n        migrations.AddField(\n            model_name='textanswer',\n            name='uuid',\n            field=models.UUIDField(null=True),\n        ),\n        migrations.RunPython(fill_textanswer_uuid, migrations.RunPython.noop),\n        migrations.AlterField(\n            model_name='textanswer',\n            name='uuid',\n            field=models.UUIDField(primary_key=False, default=uuid.uuid4, serialize=False, editable=False),\n        ),\n        # rename the old id field before deleting it at the end of the\n        # migration for compatibility with the sqlite driver\n        migrations.RenameField(\n            model_name='textanswer',\n            old_name='id',\n            new_name='old_id'\n        ),\n        migrations.RenameField(\n            model_name='textanswer',\n            old_name='uuid',\n            new_name='id'\n        ),\n        migrations.AlterField(\n            model_name='textanswer',\n            name='id',\n            field=models.UUIDField(primary_key=True, default=uuid.uuid4, serialize=False, editable=False),\n        ),\n        migrations.AlterModelOptions(\n            name='textanswer',\n            options={'ordering': ['id'], 'verbose_name': 'text answer', 'verbose_name_plural': 'text answers'},\n        ),\n        migrations.RemoveField(model_name='textanswer', name='old_id'),\n    ]\n", "path": "evap/evaluation/migrations/0062_replace_textanswer_id_with_uuid.py"}]}