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/articles/migrations/0001_initial.py

@@ -0,0 +1,26 @@
+# Generated by Django 2.0 on 2017-12-05 04:05
+
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    initial = True
+
+    dependencies = [
+    ]
+
+    operations = [
+        migrations.CreateModel(
+            name='Article',
+            fields=[
+                ('id', models.AutoField(auto_created=True, primary_key=True, serialize=False, verbose_name='ID')),
+                ('title', models.CharField(help_text='Main article headline', max_length=255, unique=True)),
+                ('body', models.TextField(help_text='Article content', max_length=5000)),
+                ('slug', models.SlugField(blank=True, help_text='Unique URL slug identifying the article', unique=True)),
+                ('date_created', models.DateTimeField(auto_now_add=True)),
+                ('date_modified', models.DateTimeField(auto_now=True)),
+                ('cover', models.ImageField(blank=True, upload_to='article/original/')),
+            ],
+        ),
+    ]