fix unit tests for reorganized codebase

test/src/test_FileLoader.cc

@@ -1,5 +1,5 @@
 #include "gtest/gtest.h"
-#include "jes/FileLoader.h"
+#include "FileLoader.h"
 
 using namespace jes;
 

test/src/test_Path.cc

@@ -1,5 +1,5 @@
 #include "gtest/gtest.h"
-#include "jes/Path.h"
+#include "Path.h"
 #include <algorithm>
 
 using namespace jes;

test/src/test_Ref.cc

@@ -1,5 +1,5 @@
 #include "gtest/gtest.h"
-#include "jes/Ref.h"
+#include "Ref.h"
 #include <algorithm>
 
 using namespace jes;