Add GTK UI Skeleton.

dsst/dsst_gtk3/gtk_ui.py

@@ -0,0 +1,16 @@
+import gi
+import os
+
+gi.require_version('Gtk', '3.0')
+from gi.repository import Gtk
+
+
+class DSSTGtkUi:
+    def __init__(self):
+        self.ui = Gtk.Builder()
+        self.ui.add_from_file(os.path.join(os.path.dirname(__file__), 'resources', 'glade', 'window.glade'))
+        self.ui.get_object('main_window').show_all()
+
+if __name__ == '__main__':
+    DSSTGtkUi()
+    Gtk.main()