Refactor

As all points from the epic refactor issue are closed #47 (closed) I am merging this in to master in order to unblock development.

backend/core/migrations/0001_initial.py

@@ -56,7 +56,6 @@ class Migration(migrations.Migration):
                 ('score', models.PositiveIntegerField(default=0)),
                 ('created', models.DateTimeField(auto_now_add=True)),
                 ('modified', models.DateTimeField(auto_now=True)),
-                ('slug', models.SlugField(default=core.models.random_slug, editable=False, unique=True)),
                 ('status', models.IntegerField(choices=[(0, 'editable'), (1, 'request reassignment'), (2, 'request review'), (3, 'accepted')], default=0)),
                 ('origin', models.IntegerField(choices=[(0, 'was empty'), (1, 'passed unittests'), (2, 'did not compile'), (3, 'could not link'), (4, 'created by a human. yak!')], default=4)),
             ],
@@ -77,7 +76,6 @@ class Migration(migrations.Migration):
             fields=[
                 ('id', models.AutoField(auto_created=True, primary_key=True, serialize=False, verbose_name='ID')),
                 ('has_logged_in', models.BooleanField(default=False)),
-                ('matrikel_no', models.CharField(default=core.models.random_matrikel_no, max_length=8, unique=True)),
                 ('exam', models.ForeignKey(null=True, on_delete=django.db.models.deletion.SET_NULL, related_name='students', to='core.ExamType')),
                 ('user', models.OneToOneField(on_delete=django.db.models.deletion.CASCADE, related_name='student', to=settings.AUTH_USER_MODEL)),
             ],
@@ -92,7 +90,6 @@ class Migration(migrations.Migration):
                 ('id', models.AutoField(auto_created=True, primary_key=True, serialize=False, verbose_name='ID')),
                 ('seen_by_student', models.BooleanField(default=False)),
                 ('text', models.TextField(blank=True)),
-                ('slug', models.SlugField(default=core.models.random_slug, editable=False, unique=True)),
                 ('student', models.ForeignKey(on_delete=django.db.models.deletion.CASCADE, related_name='submissions', to='core.Student')),
             ],
             options={
@@ -109,7 +106,6 @@ class Migration(migrations.Migration):
                 ('full_score', models.PositiveIntegerField(default=0)),
                 ('description', models.TextField()),
                 ('solution', models.TextField()),
-                ('slug', models.SlugField(default=core.models.random_slug, editable=False, unique=True)),
             ],
             options={
                 'verbose_name': 'SubmissionType',