Update xeus-cpp to 0.7.1 for release

Author: mcbarton

include/xeus-cpp/xeus_cpp_config.hpp

@@ -11,9 +11,8 @@
 
 // Project version
 #define XEUS_CPP_VERSION_MAJOR 0
-#define XEUS_CPP_VERSION_MINOR 8
-#define XEUS_CPP_VERSION_PATCH 0
-#define XEUS_CPP_VERSION_LABEL dev
+#define XEUS_CPP_VERSION_MINOR 7
+#define XEUS_CPP_VERSION_PATCH 1
 
 // Composing the version string from major, minor and patch
 #define XEUS_CPP_CONCATENATE(A, B) XEUS_CPP_CONCATENATE_IMPL(A, B)