Add test target to Makefile

Signed-off-by: martin f. krafft <madduck@madduck.net>
diff --git a/Makefile b/Makefile
index 0f7eb77..98ac77b 100644
--- a/Makefile
+++ b/Makefile
@@ -6,6 +6,10 @@
 #
 PYFILES = $(shell find -name .git -o -name dist -o -name build -prune -o -name '*.py' -print)
 
+tests:
+	python setup.py nosetests
+.PHONY: tests
+
 lint:
 	@echo pylint --rcfile=.pylintrc $(ARGS) …
 	@pylint --rcfile=.pylintrc $(ARGS) $(PYFILES)