clutter-gstreamer test: check dependency version

Clutter-GStreamer 2.0 can't be used on Travis CI yet.
Don't run gtk3-gi test

Because it's an experimental module. It can run separate:

    % ./gtk3-gi/test/run-test.rb
clutter-gstreamer test: use ENV["CI"] for omitted condition

Because the following error occurred on Travis CI:

    ===============================================================================
    Error: test_init(ClutterGstTest)
    GLib::Error: Requiring namespace 'GstBase' version '0.10', but '1.0' is already loaded
    /home/travis/build/ruby-gnome2/ruby-gnome2/gobject-introspection/lib/gobject-introspection/loader.rb:35:in `require'
    /home/travis/build/ruby-gnome2/ruby-gnome2/gobject-introspection/lib/gobject-introspection/loader.rb:35:in `load'
    /home/travis/build/ruby-gnome2/ruby-gnome2/clutter-gstreamer/lib/clutter-gst.rb:49:in `init'
    /home/travis/build/ruby-gnome2/ruby-gnome2/clutter-gstreamer/lib/clutter-gst.rb:33:in `const_missing'
    /home/travis/build/ruby-gnome2/ruby-gnome2/clutter-gstreamer/test/clutter-gstreamer-test-utils.rb:24:in `later_version?'
    /home/travis/build/ruby-gnome2/ruby-gnome2/clutter-gstreamer/test/clutter-gstreamer-test-utils.rb:33:in `only_clutter_gstreamer_version'
    /home/travis/build/ruby-gnome2/ruby-gnome2/clutter-gstreamer/test/test-clutter-gst.rb:21:in `test_init'
         18:   include ClutterGStreamerTestUtils
         19:
         20:   def test_init
      => 21:     only_clutter_gstreamer_version(2, 0, 0)
         22:     assert_nothing_raised do
         23:       ClutterGst.init
         24:     end
    ===============================================================================
gio2: add cancellable argument into Gio::InputStream#read
Revert "gio2: add cancellable argument into Gio::InputStream#read"

This reverts commit c5f8c58eed5a83db5191ee1447ed6e394f365942.

Ruby 1.9 series cannot use keyword arguments.
Oh....
update for gtk3
Merge pull request #242 from kitachro/master

gtk3/sample/misxcupdate for gtk3

Patch by kitachro. Thanks!!!
update for gtk3
Merge remote-tracking branch 'upstream/master'
supress warnings
Merge pull request #243 from kitachro/master

fix gtk3/sample/misc/ scripts

Patch by kitachro. Thanks!!!
make a sample script gtk3 ready

gtk3/sample/misc/assistant.rb
* add "round" method call for "progress.fraction" value not to exceed 1.0.
* remove the last "full_featured_assistant" sample because Gtk::Assistant#set_page_side_image and Gtk::Assistant#set_page_header_image methods have been deprecated and there is no alternative method.
Merge pull request #244 from kitachro/assistantrb

Make one sample script gtk3 ready

Patch by kitachro. Thanks!!!
gtk3: modify deprecated constants

gtk3/sample/misc/bindings.rb
gtk3: modify deprecated class names

gtk3/sample/misc/bindings.rb
gtk3: modify method calls with deprecated argument style

gtk3/sample/misc/binding.rb
gtk3: modify deprecated method calls

gtk3/sample/misc/bindings.rb
* Remove a Gtk::BindingSet#add_path method call.
* Replace Gtk::BindingSet#entry_clear method calls with Gtk::BindingSet#entry_remove.
Merge pull request #246 from kitachro/bindingsrb

gtk3: make one sample script gtk3 ready

Patch by kitachro. Thanks!!!
gtk3 sample: remove BOM
gtk3: modify a method call with a deprecated argument style