Apprise notifications (#43)

* issue #4 Adding settings screen for apprise URLS
* Adding test notification mechanism

* Move Worker module to own class file

* Adding basic notification URL runner

* Tests for notifications

* Tweak readme with notification info

* Move notification test to main test_backend.py

* Fix spacing

* Adding notifications screenshot

* Cleanup more files from test

* Offer send notification test on individual edits and main/default

* Process global notifications

* All branches test

* Wrap worker notification process in try/catch, use global if nothing set

* Fix syntax

* Handle exception, increase wait time for liveserver to come up

* Fixing test setup

* remove debug

* Split tests into their own totally isolated setups, if you know a better way to make live_server() work, MR :)

* Tidying up lint/imports

backend/tests/conftest.py

@@ -35,13 +35,12 @@ def app(request):
     def teardown():
         datastore.stop_thread = True
         app.config.exit.set()
-        try:
-            os.unlink("{}/url-watches.json".format(datastore_path))
-        except FileNotFoundError:
-            # This is fine in the case of a failure.
-            pass
-
-        assert 1 == 1
+        for fname in ["url-watches.json", "count.txt", "output.txt"]:
+            try:
+                os.unlink("{}/{}".format(datastore_path, fname))
+            except FileNotFoundError:
+                # This is fine in the case of a failure.
+                pass
 
     request.addfinalizer(teardown)
     yield app