Update python code blocks for syntax highlighting

docs/tutorial/quickstart.md

@@ -65,6 +65,7 @@ Once you've set up a database and initial user created and ready to go, open up
 
 First up we're going to define some serializers. Let's create a new module named `tutorial/quickstart/serializers.py` that we'll use for our data representations.
 
+```python
 from django.contrib.auth.models import User, Group
 from rest_framework import serializers
 
@@ -79,6 +80,7 @@ First up we're going to define some serializers. Let's create a new module named
     class Meta:
         model = Group
         fields = ('url', 'name')
+```
 
 Notice that we're using hyperlinked relations in this case, with `HyperlinkedModelSerializer`.  You can also use primary key and various other relationships, but hyperlinking is good RESTful design.
 
@@ -86,6 +88,7 @@ Notice that we're using hyperlinked relations in this case, with `HyperlinkedMod
 
 Right, we'd better write some views then.  Open `tutorial/quickstart/views.py` and get typing.
 
+```python
 from django.contrib.auth.models import User, Group
 from rest_framework import viewsets
 from tutorial.quickstart.serializers import UserSerializer, GroupSerializer
@@ -105,6 +108,7 @@ Right, we'd better write some views then.  Open `tutorial/quickstart/views.py` a
     """
     queryset = Group.objects.all()
     serializer_class = GroupSerializer
+```
 
 Rather than write multiple views we're grouping together all the common behavior into classes called `ViewSets`.
 
@@ -114,6 +118,7 @@ We can easily break these down into individual views if we need to, but using vi
 
 Okay, now let's wire up the API URLs.  On to `tutorial/urls.py`...
 
+```python
 from django.conf.urls import url, include
 from rest_framework import routers
 from tutorial.quickstart import views
@@ -128,6 +133,7 @@ Okay, now let's wire up the API URLs.  On to `tutorial/urls.py`...
     url(r'^', include(router.urls)),
     url(r'^api-auth/', include('rest_framework.urls', namespace='rest_framework'))
 ]
+```
 
 Because we're using viewsets instead of views, we can automatically generate the URL conf for our API, by simply registering the viewsets with a router class.
 
@@ -139,6 +145,7 @@ Finally, we're including default login and logout views for use with the browsab
 
 We'd also like to set a few global settings.  We'd like to turn on pagination, and we want our API to only be accessible to admin users.  The settings module will be in `tutorial/settings.py`
 
+```python
 INSTALLED_APPS = (
     ...
     'rest_framework',
@@ -148,6 +155,7 @@ We'd also like to set a few global settings.  We'd like to turn on pagination, a
     'DEFAULT_PERMISSION_CLASSES': ('rest_framework.permissions.IsAdminUser',),
     'PAGE_SIZE': 10
 }
+```
 
 Okay, we're done.