Made tz data location user-configurable (#238)

config/prod.exs

@@ -7,8 +7,6 @@ import Config
 # before starting your production server.
 config :pinchflat, PinchflatWeb.Endpoint, cache_static_manifest: "priv/static/cache_manifest.json"
 
-config :tzdata, :data_dir, "/etc/elixir_tzdata_data"
-
 # Configures Swoosh API Client
 config :swoosh, api_client: Swoosh.ApiClient.Finch, finch_name: Pinchflat.Finch
 

config/runtime.exs

@@ -66,6 +66,8 @@ if config_env() == :prod do
     expose_feed_endpoints: expose_feed_endpoints,
     timezone: System.get_env("TIMEZONE") || System.get_env("TZ") || "UTC"
 
+  config :tzdata, :data_dir, System.get_env("TZ_DATA_DIR", "/etc/elixir_tzdata_data")
+
   config :pinchflat, Pinchflat.Repo,
     database: db_path,
     journal_mode: journal_mode