Add example for the weak linking

examples/weak_linking/test/main.test.c

@@ -0,0 +1,28 @@
+
+#include "display.fake.h"
+#include "sensor.fake.h"
+#include "test_common.h"
+
+DEFINE_FFF_GLOBALS;
+
+int update_main( void );
+
+int main(void)
+{
+    
+   init_tests(); // will reset common and hook errors to asserts
+   
+   sensor_init_fake.return_val = true;
+   display_init_fake.return_val = true;
+   
+   update_main();
+   
+   assert( sensor_init_fake.call_count == 1 );
+   assert( display_init_fake.call_count == 1 );
+   assert( display_update_fake.call_count == 1 );
+   
+   printf("Test " __FILE__ " ok\n");
+   return 0;
+
+}
+