Moved source files to src/

Change-Id: I07939335ddc6383ce64a8812476e09f3a23f1d7d
diff --git a/sim/hei_sim_main.cpp b/sim/hei_sim_main.cpp
index b3f26d2..035d003 100644
--- a/sim/hei_sim_main.cpp
+++ b/sim/hei_sim_main.cpp
@@ -1,5 +1,5 @@
 
-#include "../hei_isolator.hpp"
+#include "../src/hei_isolator.hpp"
 
 int main()
 {