Require Gtk and WebKit versions on import

Signed-off-by: somas95 <manuel.genoves@gmail.com>

uberwriter/UberwriterWindow.py

@@ -27,6 +27,8 @@ locale.textdomain('uberwriter')
 
 import mimetypes
 
+import gi
+gi.require_version('WebKit2', '4.0')
 from gi.repository import Gtk, Gdk, GObject, Gio  # pylint: disable=E0611
 from gi.repository import WebKit2 as WebKit
 from gi.repository import Pango  # pylint: disable=E0611

uberwriter/__init__.py

@@ -21,6 +21,8 @@ import os
 from locale import gettext as _
 locale.textdomain('uberwriter')
 
+import gi
+gi.require_version('Gtk', '3.0')
 from gi.repository import Gtk # pylint: disable=E0611
 
 from . import UberwriterWindow