Remove calls to Mix as it is not available in releases

lib/recycledcloud.ex

@@ -6,4 +6,12 @@ defmodule RecycledCloud do
   Contexts are also responsible for managing your data, regardless
   if it comes from the database, an external API or others.
   """
+
+  # Mix is not available in releases, and these things are static
+  # anyway (@variables are evaluated at compile time).
+  @version Mix.Project.config[:version]
+  @env Mix.env
+
+  def version, do: @version
+  def env, do: @env
 end

lib/recycledcloud_web/router.ex

@@ -69,7 +69,7 @@ defmodule RecycledCloudWeb.Router do
 
   # In-memory mailer for development purposes only.
   # See https://hexdocs.pm/bamboo/Bamboo.SentEmailViewerPlug.html for details.
-  if Mix.env == :dev do
+  if RecycledCloud.env() == :dev do
     forward "/outbox", Bamboo.SentEmailViewerPlug
   end
 end

lib/recycledcloud_web/templates/layout/app.html.eex

@@ -15,7 +15,7 @@
           <img id="nav-logo" src="<%= Routes.static_path(@conn, "/images/cloud.svg") %>"></img>
           <p class="nav-notice">
             <small>
-              management v<%= Mix.Project.config[:version] %> | <%= Mix.env %> | <a href="https://code.recycled.cloud/e-Durable/management">sources</a>
+              management v<%= RecycledCloud.version() %> | <%= RecycledCloud.env() %> | <a href="https://code.recycled.cloud/e-Durable/management">sources</a>
             </small>
           </p>
         </div>