tests: add initial unit test env

CMakeLists.txt

@@ -1,4 +1,4 @@
-cmake_minimum_required (VERSION 2.6)
+cmake_minimum_required (VERSION 2.8)
 project (maa)
 
 set(SWIG_EXECUTABLE /usr/bin/swig)
@@ -7,6 +7,13 @@ INCLUDE(${SWIG_USE_FILE})
 
 SET(CMAKE_SWIG_FLAGS "")
 
+option(test "Build all tests." OFF)
+
 add_subdirectory (src)
 add_subdirectory (api)
 add_subdirectory (examples)
+
+if (test)
+  enable_testing ()
+  add_subdirectory (tests)
+endif()