Fix various warning while running app and tests

.pylintrc

@@ -7,4 +7,5 @@
 disable=attribute-defined-outside-init,
 	duplicate-code,
 	fixme,
-        missing-docstring
+        missing-docstring,
+        wrong-import-position

setup.cfg

+[pycodestyle]
+ignore = E126,E402

src/briar-gtk.in

@@ -13,8 +13,6 @@ import os
 import signal
 import sys
 
-import gi
-gi.require_version('Gtk', '3.0')
 from gi.repository import Gio
 
 PACKAGE_DATA_DIR = '@PACKAGE_DATA_DIR@'

src/briar/gtk/application.py

@@ -6,6 +6,9 @@
 # Initial version based on GNOME Lollypop
 # https://gitlab.gnome.org/World/lollypop/blob/1.0.2/lollypop/application.py
 
+import gi
+gi.require_version('Gdk', '3.0')
+gi.require_version('Gtk', '3.0')
 from gi.repository import Gdk, Gio, GLib, Gtk
 
 from briar_wrapper.api import Api

tests/briar/gtk/test_application.py

@@ -4,6 +4,8 @@
 
 from unittest.mock import Mock
 
+import pytest
+
 from briar_wrapper.api import Api
 from briar.gtk.application import Application
 from briar.gtk.define import APPLICATION_NAME, APPLICATION_STYLING_PATH
@@ -137,3 +139,8 @@ def test_setup_window_has_none_attribute(mocker):
 
     window_show_mock.assert_called_once()
     window_present_mock.assert_called_once()
+
+
+@pytest.fixture(autouse=True)
+def glib_set_application_name(mocker):
+    mocker.patch("gi.repository.GLib.set_application_name")

tests/conftest.py

@@ -27,5 +27,5 @@ def auth_token():
 def request_headers(auth_token):
     request_headers = {
         "Authorization": 'Bearer %s' % auth_token
-        }
+    }
     return request_headers