Include <algorithm> for std::min

This fixes building the test code on MSVC 2013.

(Actually building all of the tests on windows still is tricky
due to the OpenSSL dependency for SHA1, but there's a patchset
in review to take care of that.)

test/utils/BufferedData.h

@@ -4,6 +4,7 @@
 #include <stddef.h>
 #include <stdlib.h>
 #include <stdint.h>
+#include <algorithm>
 
 class BufferedData {
  public: