run tests/setup in a virtualenv

Makefile

@@ -1,12 +1,13 @@
 setup:
-	@pip install --requirement=REQUIREMENTS
+	@virtualenv venv
+	@venv/bin/pip install --requirement=REQUIREMENTS
 
 docs:
-	@python docs.py
+	@venv/bin/python docs.py
 
 test:
-	@env PYTHONHASHSEED=random PYTHONPATH=. nosetests --with-coverage --cover-package=provy --cover-erase --with-yanc --with-xtraceback tests/
+	@env PYTHONHASHSEED=random PYTHONPATH=. venv/bin/nosetests --with-coverage --cover-package=provy --cover-erase --with-yanc --with-xtraceback tests/
 
 build: test
 	@echo Running syntax check...
-	@flake8 . --ignore=E501
+	@venv/bin/flake8 . --ignore=E501 --exclude=*/venv/*