ADD: support for pylint.

.buildbot/test/01-requirements.sh

@@ -3,3 +3,4 @@ if test "$python_major_version" = "2" ; then
 	pip install 'django<2'
 fi
 pip install -r requirements.txt
+pip install pylint

.buildbot/test/70-pylint.sh

@@ -0,0 +1 @@
+pylint apps.base