[Cmake] use Python SOABI, ref #55

CMakeLists.txt

@@ -116,6 +116,7 @@ SET(${PROJECT_NAME}_SOURCES
 )
 
 ADD_LIBRARY(${PROJECT_NAME} SHARED ${${PROJECT_NAME}_SOURCES} ${${PROJECT_NAME}_HEADERS})
+SET_TARGET_PROPERTIES(${PROJECT_NAME} PROPERTIES OUTPUT_NAME "${PROJECT_NAME}${PYTHON_SOABI}")
 
 TARGET_LINK_BOOST_PYTHON(${PROJECT_NAME})
 PKG_CONFIG_USE_DEPENDENCY(${PROJECT_NAME} eigen3)