Explicitly point to use python3

Change-Id: Ia2e4c11977cf2ed10958a0624344504ce54685e9
Signed-off-by: Vishwanatha Subbanna <vishwa@linux.vnet.ibm.com>
diff --git a/configure.ac b/configure.ac
index f9ddc4b..9529fe9 100644
--- a/configure.ac
+++ b/configure.ac
@@ -16,7 +16,7 @@
 AX_APPEND_COMPILE_FLAGS([-Wall -Werror], [CXXFLAGS])
 
 # Python
-AM_PATH_PYTHON([2.7], [AC_SUBST([PYTHON], [echo "$PYTHON"])], [AC_MSG_ERROR([Could not find python-2.7 installed...python-2.7 is required])])
+AM_PATH_PYTHON([3], [AC_SUBST([PYTHON], [echo "$PYTHON"])], [AC_MSG_ERROR([Could not find python-3 installed...python-3 is required])])
 
 LT_INIT # Removes WARNING: unrecognized options: --with-libtool-sysroot
 # Check/set gtest specific functions.