version bump to 0.31
diff --git a/Makefile b/Makefile
index fb8f917..d11442c 100644
--- a/Makefile
+++ b/Makefile
@@ -1,4 +1,4 @@
-VERSION_STRING = "0.30"
+VERSION_STRING = "0.31"
 
 TARGETS	= cyclictest signaltest classic_pi pi_stress
 FLAGS	= -Wall -Wno-nonnull -O2