Add few unit tests for Caca::Display

ruby/t/tc_display.rb

@@ -0,0 +1,24 @@
+require 'test/unit'
+require 'caca'
+
+class TC_Canvas < Test::Unit::TestCase
+    def test_create
+	d = Caca::Display.new
+        assert_not_nil(d, 'Display creation failed')
+    end
+    def test_create_with_driver
+	d = Caca::Display.new(nil, Caca::Display.driver_list[0])
+        assert_not_nil(d, 'Display creation failed')
+    end
+    def test_create_from_canvas
+        c = Cucul::Canvas.new(3, 3)
+	d = Caca::Display.new(c)
+        assert_not_nil(d, 'Display creation failed')
+	assert_equal(d.canvas, c, 'Wrong canvas')
+    end
+    def test_set_title
+        c = Cucul::Canvas.new(3, 3)
+        d = Caca::Display.new(c)
+        d.title = "Test !"
+    end
+end