update .clang-format header inclusion order

Added the header inclusion order to the .clang-format file generated
these changes.

Change-Id: Ia31b21d7ea451cac0309828006bc17c27cbd5bd5
Signed-off-by: Patrick Venture <venture@google.com>
diff --git a/mapbox/variant.hpp b/mapbox/variant.hpp
index 46db853..2019fc5 100644
--- a/mapbox/variant.hpp
+++ b/mapbox/variant.hpp
@@ -2,7 +2,8 @@
 #define MAPBOX_UTIL_VARIANT_HPP
 
 #include <cassert>
-#include <cstddef>   // size_t
+#include <cstddef> // size_t
+#include <mapbox/recursive_wrapper.hpp>
 #include <new>       // operator new
 #include <stdexcept> // runtime_error
 #include <string>
@@ -11,8 +12,6 @@
 #include <typeinfo>
 #include <utility>
 
-#include <mapbox/recursive_wrapper.hpp>
-
 // clang-format off
 // [[deprecated]] is only available in C++14, use this for the time being
 #if __cplusplus <= 201103L