re/moved some headers in catch_tostring

include/internal/catch_tostring.cpp

@@ -10,6 +10,8 @@
 #include "catch_interfaces_config.h"
 #include "catch_context.h"
 
+#include <iomanip>
+
 namespace Catch {
 
 namespace Detail {

include/internal/catch_tostring.h

@@ -11,8 +11,6 @@
 #include "catch_common.h"
 
 #include <sstream>
-#include <iomanip>
-#include <limits>
 #include <vector>
 #include <cstddef>