adding boost filesystem include to service registry impl

Signed-off-by: Alex McCaskey <mccaskeyaj@ornl.gov>

xacc/utils/ServiceRegistry.cpp

 #include "ServiceRegistry.hpp"
+#include <boost/filesystem.hpp>
 
-#include <dirent.h>
 namespace xacc {
+
 void ServiceRegistry::initialize() {
 
 	if (!initialized) {

xacc/utils/ServiceRegistry.hpp

@@ -32,7 +32,6 @@
 #include <map>
 #include <iostream>
 #include <boost/program_options.hpp>
-#include <boost/filesystem.hpp>
 #include <dirent.h>
 
 using namespace boost::program_options;