- Added generic 'make check' in Makefile

diff --git a/Makefile b/Makefile
index 2a1ba2d..5c7bc7b 100644
--- a/Makefile
+++ b/Makefile
@@ -30,3 +30,5 @@
 	cd programs && make clean && cd ..
 	cd tests && make clean && cd ..
 
+check:
+	( cd tests && make check )