Add make target for testing python2.7

Author: jonathanlloyd

Makefile

@@ -18,6 +18,13 @@ check: test
 test: venv
 	@venv/bin/python3 -m nose -s
 
+test_python2: venv
+	@rm -rf venv
+	@python2.7 -m virtualenv venv
+	@venv/bin/pip install -Ur requirements.txt
+	@venv/bin/pip install -Ur dev_requirements.txt
+	@venv/bin/python2.7 -m nose -s
+
 lint: venv
 	@venv/bin/python3 -m pylint ./pusher_push_notifications/*.py