[Enhancement] Add Apprise support (#170)

* [WIP] add settings sidebar entry and placeholder page

* [WIP] added placeholder UI and logic for settings form

* Added column and UI for apprise server

* Add some tests

* Added placeholder command runner for apprise

* [WIP] Adding apprise package

* Added apprise command runner

* Hooked up apprise notification module

* Ensured apprise was running in verbose mode

* Updated wording of apprise notification

* Added apprise to README

test/pinchflat_web/controllers/setting_controller_test.exs

@@ -0,0 +1,23 @@
+defmodule PinchflatWeb.SettingControllerTest do
+  use PinchflatWeb.ConnCase
+
+  describe "show settings" do
+    test "renders the page", %{conn: conn} do
+      conn = get(conn, ~p"/settings")
+
+      assert html_response(conn, 200) =~ "Settings"
+    end
+  end
+
+  describe "update settings" do
+    test "saves and redirects when data is valid", %{conn: conn} do
+      update_attrs = %{apprise_server: "test://server"}
+
+      conn = put(conn, ~p"/settings", setting: update_attrs)
+      assert redirected_to(conn) == ~p"/settings"
+
+      conn = get(conn, ~p"/settings")
+      assert html_response(conn, 200) =~ update_attrs[:apprise_server]
+    end
+  end
+end