Set default email sender to hi@towerops.net

Configure mailer_from in runtime config and update UserNotifier
and AlertNotifier to use the configured from address.

config/runtime.exs

@@ -134,4 +134,7 @@ if config_env() == :prod do
     secret_key_base: secret_key_base
 
   config :towerops, :dns_cluster_query, System.get_env("DNS_CLUSTER_QUERY")
+
+  # Set default sender for all emails
+  config :towerops, :mailer_from, {"Towerops", "hi@towerops.net"}
 end

lib/towerops/accounts/user_notifier.ex

@@ -7,10 +7,12 @@ defmodule Towerops.Accounts.UserNotifier do
 
   # Delivers the email using the application mailer.
   defp deliver(recipient, subject, body) do
+    from_address = Application.get_env(:towerops, :mailer_from, {"Towerops", "hi@towerops.net"})
+
     email =
       new()
       |> to(recipient)
-      |> from({"Towerops", "contact@example.com"})
+      |> from(from_address)
       |> subject(subject)
       |> text_body(body)
 

lib/towerops/alerts/alert_notifier.ex

@@ -90,10 +90,12 @@ defmodule Towerops.Alerts.AlertNotifier do
   end
 
   defp deliver(recipient, subject, body) do
+    from_address = Application.get_env(:towerops, :mailer_from, {"Towerops", "hi@towerops.net"})
+
     email =
       new()
       |> to(recipient)
-      |> from({"TowerOps Alerts", "alerts@towerops.example.com"})
+      |> from(from_address)
       |> subject(subject)
       |> text_body(body)