Switch to 4.2a9 version

Author: dellaert

CMakeLists.txt

@@ -10,7 +10,7 @@ endif()
 set (GTSAM_VERSION_MAJOR 4)
 set (GTSAM_VERSION_MINOR 2)
 set (GTSAM_VERSION_PATCH 0)
-set (GTSAM_PRERELEASE_VERSION "")
+set (GTSAM_PRERELEASE_VERSION "a9")
 math (EXPR GTSAM_VERSION_NUMERIC "10000 * ${GTSAM_VERSION_MAJOR} + 100 * ${GTSAM_VERSION_MINOR} + ${GTSAM_VERSION_PATCH}")
 
 if (${GTSAM_VERSION_PATCH} EQUAL 0)