clarify required setup (see #16)

Author: sheppard

README.md

@@ -78,7 +78,9 @@ urlpatterns = [
 
 > Note: If you are upgrading from 1.0, you will need to update your URLs to add the `datawizard/` prefix as shown above.
 
-Finally, register one or more target models with the wizard.  Like the Django admin and `admin.py`, Data Wizard will look for a `wizard.py` file in your app directory:
+### Model Registration
+
+In order to use the wizard, you must register one or more target models and/or serializers.  Like the Django admin and `admin.py`, Data Wizard will look for a `wizard.py` file in your app directory:
 
 ```python
 # myapp/wizard.py
@@ -88,7 +90,7 @@ from .models import MyModel
 data_wizard.register(MyModel)
 ```
 
-If needed, you can use a [custom serializer class](#custom-serializers) to configure how the target model is validated and populated.
+The wizard will automatically create a serializer class corresponding to the target model.  If needed, you can also use a [custom serializer class](#custom-serializers) to configure how the target model is validated and populated.
 
 Once everything is configured, create a data source in the Django admin, select "Import via data wizard" from the admin actions menu, and navigate through the screens described below.
 

data_wizard/templates/data_wizard/run_serializers.html

@@ -9,6 +9,11 @@ <h2>Data Format</h2>
   </li>
 </ul>
 {% include "data_wizard/continue.html" %}
+{% elif not serializer_choices %}
+<ul class="messagelist">
+  <li class="error">No serializers registered.</li>
+</ul>
+<p>See <a href="https://github.com/wq/django-data-wizard#model-registration">https://github.com/wq/django-data-wizard#model-registration</a> for more information.
 {% else %}
 <ul class="messagelist">
   <li class="warning">Select a format (serializer) to continue.</li>

setup.py

@@ -41,6 +41,7 @@ def readme():
         ]
     },
     install_requires=[
+        'djangorestframework',
         'wq.io',
         'natural-keys',
         'html-json-forms',