Rewrite schema generation (#1)

* Completeley rewritten schema generation
* Added support for python 2.7 and 3.4
* Restructured testing and build configuration
* Added nested request schemas

This rewrite completely replaces the public interface of the django rest schema generation library, so 
further changes will be needed to re-enable and further extend the customization points one might want.

testproj/snippets/migrations/0002_auto_20171205_0505.py

@@ -0,0 +1,27 @@
+# Generated by Django 2.0 on 2017-12-05 04:05
+
+from django.conf import settings
+from django.db import migrations, models
+import django.db.models.deletion
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        migrations.swappable_dependency(settings.AUTH_USER_MODEL),
+        ('snippets', '0001_initial'),
+    ]
+
+    operations = [
+        migrations.AddField(
+            model_name='snippet',
+            name='owner',
+            field=models.ForeignKey(default='', on_delete=django.db.models.deletion.CASCADE, related_name='snippets', to=settings.AUTH_USER_MODEL),
+            preserve_default=False,
+        ),
+        migrations.AlterField(
+            model_name='snippet',
+            name='code',
+            field=models.TextField(help_text='code model help text'),
+        ),
+    ]