add 1.5.5 tag
diff --git a/CMakeLists.txt b/CMakeLists.txt
index c111500..f19390a 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -29,7 +29,7 @@
 # https://www.khronos.org/registry/spir-v/
 #
 cmake_minimum_required(VERSION 3.0)
-project(SPIRV-Headers VERSION 1.5.1)
+project(SPIRV-Headers VERSION 1.5.5)
 
 # There are two ways to use this project.
 #