extending X.t

Test for two constans from this module.
This is done in preparation for fixing #87.

t/X.t

@@ -1,20 +1,12 @@
-# Before `make install' is performed this script should be runnable with
-# `make test'. After `make install' it should work as `perl test.pl'
+use strict;
+use warnings;
+use Scalar::Util qw(looks_like_number);
 
-######################### We start with some black magic to print on failure.
+use Test::More;
+plan tests => 2;
 
-# Change 1..1 below to 1..last_test_to_print .
-# (It may become useful if the test is moved to ./t subdirectory.)
-
-BEGIN { $| = 1; print "1..1\n"; }
-END {print "not ok 1\n" unless $loaded;}
 use Tk::X;
-$loaded = 1;
-print "ok 1\n";
-
-######################### End of black magic.
-
-# Insert your test code below (better if it prints "ok 13"
-# (correspondingly "not ok 13") depending on the success of chunk 13
-# of the test code):
+use Tk::X qw(None ControlMask);
 
+ok looks_like_number(None),        "None looks like a number (it's @{[ None ]})";
+ok looks_like_number(ControlMask), "ControlMask looks like a number (it's @{[ ControlMask ]})";