Split requirements files

Remove unused import

src/requirements.txt

@@ -1,32 +1,4 @@
-# Functional requirements
+-r requirements/production.txt
-Django==1.8b2
+-r requirements/py33.txt
-pytz
+-r requirements/dev.txt
-django-bootstrap3
+-r requirements/testing.txt
--e git+https://github.com/pretix/django-formset-js.git@master#egg=django-formset-js
--e git+https://github.com/pretix/cleanerversion.git@pretix#egg=cleanerversion
-django-compressor
-
-# Deployment / static file compilation requirements
-BeautifulSoup4
-html5lib
-slimit
-lxml
-
-# Polyfill for Python <3.4
-# Remove this, when Python 3.3 support is dropped
-flufl.enum
-
-# Debugging requirements
-django-debug-toolbar>=1.3.0
-
-# Testing requirements
-pyflakes
-pep8==1.5.7  # exact requirement by flake8 2.4.0
-pep8-naming
-flake8
-coveralls
-coverage
-selenium
-# PyVirtualDisplay
-# -e git+https://github.com/pretix/sauceclient.git@master#egg=sauceclient
-# travis

src/requirements/dev.txt

@@ -0,0 +1 @@
+django-debug-toolbar>=1.3.0

src/requirements/production.txt

@@ -0,0 +1,13 @@
+# Functional requirements
+Django==1.8b2
+pytz
+django-bootstrap3
+-e git+https://github.com/pretix/django-formset-js.git@master#egg=django-formset-js
+-e git+https://github.com/pretix/cleanerversion.git@pretix#egg=cleanerversion
+django-compressor
+
+# Deployment / static file compilation requirements
+BeautifulSoup4
+html5lib
+slimit
+lxml

src/requirements/py33.txt

@@ -0,0 +1,3 @@
+# Polyfill for Python <3.4
+# Remove this, when Python 3.3 support is dropped
+flufl.enum

src/requirements/testing.txt

@@ -0,0 +1,11 @@
+# Testing requirements
+pyflakes
+pep8==1.5.7  # exact requirement by flake8 2.4.0
+pep8-naming
+flake8
+coveralls
+coverage
+selenium
+# PyVirtualDisplay
+# -e git+https://github.com/pretix/sauceclient.git@master#egg=sauceclient
+# travis

src/tests/presale/test_checkout.py

@@ -5,7 +5,7 @@ from django.test import TestCase
 from django.utils.timezone import now
 from datetime import timedelta
 
-from pretix.base.models import Item, Organizer, Event, ItemCategory, Quota, Property, PropertyValue, ItemVariation, User, \
+from pretix.base.models import Item, Organizer, Event, ItemCategory, Quota, User, \
     CartPosition, Question, Order, OrderPosition