python: Support building of both python2 & python3 bindings

Signed-off-by: Brendan Le Foll <brendan.le.foll@intel.com>

src/python/python3/CMakeLists.txt

@@ -0,0 +1,24 @@
+set_source_files_properties (mraa3.i PROPERTIES CPLUSPLUS ON)
+set_source_files_properties (mraa3.i PROPERTIES SWIG_FLAGS "-I${CMAKE_BINARY_DIR}/src")
+
+if (PYTHON3_LIBRARY)
+    message ("PYTHON3 attempting to build!")
+
+    swig_add_module (python3-mraa python mraa3.i ../mraapy.c)
+    swig_link_libraries (python3-mraa ${PYTHON3_LIBRARIES} mraa)
+
+    target_include_directories(${SWIG_MODULE_python3-mraa_REAL_NAME}
+      PUBLIC
+      "${CMAKE_CURRENT_SOURCE_DIR}/../.."
+      "${PYTHON3_INCLUDE_DIR}"
+    )
+
+    set_target_properties (${SWIG_MODULE_python3-mraa_REAL_NAME} PROPERTIES
+      OUTPUT_NAME _mraa
+      COMPILE_FLAGS "${CMAKE_C_FLAGS} -DSWIGPYTHON=${SWIG_FOUND}"
+    )
+
+    install (FILES ${CMAKE_CURRENT_BINARY_DIR}/_mraa.so
+             ${CMAKE_CURRENT_BINARY_DIR}/mraa.py
+             DESTINATION ${CMAKE_INSTALL_PREFIX}/${PYTHON3_PACKAGES_PATH})
+endif ()

src/python/python3/mraa3.i

@@ -0,0 +1,3 @@
+%module(docstring="Python interface to libmraa") mraa
+
+%include ../mraapython.i