Change version to 3.4.0.

Eigen/src/Core/util/Macros.h

diff --git a/Eigen/src/Core/util/Macros.h b/Eigen/src/Core/util/Macros.h
index 518c6c1..986c3d4 100644
--- a/Eigen/src/Core/util/Macros.h
+++ b/Eigen/src/Core/util/Macros.h
@@ -16,8 +16,8 @@
 //------------------------------------------------------------------------------------------
 
 #define EIGEN_WORLD_VERSION 3
-#define EIGEN_MAJOR_VERSION 3
-#define EIGEN_MINOR_VERSION 91
+#define EIGEN_MAJOR_VERSION 4
+#define EIGEN_MINOR_VERSION 0
 
 #define EIGEN_VERSION_AT_LEAST(x,y,z) (EIGEN_WORLD_VERSION>x || (EIGEN_WORLD_VERSION>=x && \
                                       (EIGEN_MAJOR_VERSION>y || (EIGEN_MAJOR_VERSION>=y && \