header cleanups

This commit fixed several places (but not all) where wrong include
directory is specified and prevent the clean up in the chidren changes.

Signed-off-by: Nan Zhou <nanzhoumails@gmail.com>
Change-Id: Ibbba62e2c0cfe3583a65f1befa1b233bd3eebf19
diff --git a/test/include/multipart_test.cpp b/test/include/multipart_test.cpp
index f29bcfe..38ac53d 100644
--- a/test/include/multipart_test.cpp
+++ b/test/include/multipart_test.cpp
@@ -1,4 +1,4 @@
-#include "http/http_request.hpp"
+#include "http_request.hpp"
 #include "multipart_parser.hpp"
 
 #include <boost/beast/http/fields.hpp>