Disabled UNIXSocket test on Cygwin

mrbgems/mruby-socket/test/sockettest.c

@@ -26,10 +26,21 @@ mrb_sockettest_win_p(mrb_state *mrb, mrb_value klass)
 #endif
 }
 
+mrb_value
+mrb_sockettest_cygwin_p(mrb_state *mrb, mrb_value klass)
+{
+#if defined(__CYGWIN__) || defined(__CYGWIN32__)
+  return mrb_true_value();
+#else
+  return mrb_false_value();
+#endif
+}
+
 void
 mrb_mruby_socket_gem_test(mrb_state* mrb)
 {
   struct RClass *c = mrb_define_module(mrb, "SocketTest");
   mrb_define_class_method(mrb, c, "tmppath", mrb_sockettest_tmppath, MRB_ARGS_NONE());
   mrb_define_class_method(mrb, c, "win?", mrb_sockettest_win_p, MRB_ARGS_NONE());
+  mrb_define_class_method(mrb, c, "cygwin?", mrb_sockettest_cygwin_p, MRB_ARGS_NONE());
 }

mrbgems/mruby-socket/test/unix.rb

-unless SocketTest.win?
+unless SocketTest.win? || SocketTest.cygwin?
 
 def unixserver_test_block
   path = SocketTest.tmppath