Allow subtitle downloading (#11)

* Added subtitle options to media profile model

* Updated media profile form

* Adds subtitle-based options in options builder

* Updates metadata parser to include subtitles

* Adds subtitle_filepaths to media_item

* renamed video_filepath to media_filepath

* Added more fields to media profile show page

test/support/fixtures/media_fixtures.ex

@@ -15,7 +15,7 @@ defmodule Pinchflat.MediaFixtures do
       |> Enum.into(%{
         media_id: Faker.String.base64(12),
         title: Faker.Commerce.product_name(),
-        video_filepath: "/video/#{Faker.File.file_name(:video)}",
+        media_filepath: "/video/#{Faker.File.file_name(:video)}",
         channel_id: MediaSourceFixtures.channel_fixture().id
       })
       |> Pinchflat.Media.create_media_item()