Use Notification/Notifiable (#379)

* Add migrations for notifiables

* Configure spatie-backup to run as part of cron

* Convert Mailer to Notification; add pirep notifications

* Styling

composer.json

@@ -41,13 +41,14 @@
         "nwidart/laravel-modules": "5.*",
         "php-units-of-measure/php-units-of-measure": "2.1.*",
         "pragmarx/version": "0.2.*",
-        "predis/predis": "^1.1",
+        "predis/predis": "1.1.*",
         "prettus/l5-repository": "2.6.*",
         "santigarcor/laratrust": "5.2.*",
         "sebastiaanluca/laravel-helpers": "3.*",
-        "semver/semver": "^1.1",
+        "semver/semver": "1.1.*",
+        "spatie/laravel-backup": "6.3.*",
         "spatie/laravel-pjax": "1.3.*",
-        "spatie/valuestore": "^1.2",
+        "spatie/valuestore": "1.2.*",
         "symfony/polyfill-iconv": "^1.11",
         "theiconic/php-ga-measurement-protocol": "2.7.*",
         "tivie/php-os-detector": "1.1.*",