       ...>   "user" => %{
       ...>     "first_name" => "George",
       ...>     "last_name" => "C.",
+      ...>     "uid" => 358,
       ...>     "user_link" => "http://path/to/comment/user",
       ...>     "user_name" => "george"
       ...>   }

  @doc ~S"""
  Parses a comment into an attachment for Slack.

  ## Example

      iex> Slacktapped.Comments.parse_comment(
      ...> %{

      ...> %{
      ...>   "attachments" => [],
      ...>   "user" => %{
      ...>     "uid" => 357,
      ...>     "user_name" => "nicksergeant"
      ...>   },
      ...>   "beer" => %{
      ...>     "bid" => 123,
