Merge pull request #80 from dzenanz/master

BUG: fixing CMake configure error

Author: hjmjohnson

src/CMakeLists.txt

@@ -23,7 +23,7 @@ if(BUILD_DOCUMENTATION)
   # Set here the proper version of Python required to be able to build
   # tarballs for each example
   set(PYTHON_REQUIRED_VERSION 2.7)
-  if(${PYTHON_VERSION_STRING} LESS ${PYTHON_REQUIRED_VERSION})
+  if(${PYTHON_VERSION_STRING} VERSION_LESS ${PYTHON_REQUIRED_VERSION})
     message(SEND_ERROR "Building the documentation requires Python >= ${PYTHON_REQUIRED_VERSION}")
   endif()
 endif()