Test failed on Mac OS py35 and py34

[malloxpb]

tox has been found failed on Mac OS on py34 and py35 env.
Tox creates an environment that is Mac OS 10.6 for some reason and this is the traceback for the compiling error:

    In file included from scurl/cgurl.cpp:647:
    In file included from scurl/../third_party/chromium/url/third_party/mozilla/url_parse.h:8:
    ./third_party/chromium/base/strings/string16.h:207:8: error: explicit specialization of non-template struct 'hash'
    struct hash<base::string16> {
           ^   ~~~~~~~~~~~~~~~~
    In file included from scurl/cgurl.cpp:654:
    scurl/../third_party/chromium/url/gurl.h:467:8: error: no template named 'unique_ptr' in namespace 'std'
      std::unique_ptr<GURL> inner_url_;
      ~~~~~^
    2 errors generated.
    error: command '/usr/bin/clang' failed with exit status 1