server - fix tests - added reply tests

lib/myapp/data/reply.ex

@@ -38,7 +38,7 @@ defmodule MyApp.Data.Reply do
     {:ok, data} = Repo.transaction(fn ->
       thread = Repo.get_by(Data.Thread, %{ id: Map.get(params, "thread_id")})
 
-      if !thread.locked do
+      if !is_nil(thread) && !thread.locked do
         {:ok, data} = insert_changeset(%Data.Reply{}, params)
         |> Repo.insert
         |> Data.Util.process_insert_or_update

lib/myapp_web/controllers/page_controller.ex

@@ -7,7 +7,7 @@ defmodule MyAppWeb.PageController do
 
     # cache index.html if prod
     file = case System.get_env("MIX_ENV") do
-      :prod -> 
+      "prod" -> 
         Cachex.get(:myapp, "index.html")
         |> get_file
       _ -> File.read!(Application.app_dir(:myapp, "priv/static/index.html"))