@callback copy(Dropkick.File.t(), String.t(), Keyword.t()) ::
  {:ok, Dropkick.File.t()} | {:error, String.t()}

Copies the given file with the underlyning storage module. The underlyning implementation should accept the following options (besides any specific options):

• :move: Specifies if the file should be just copied or moved entirely, defaults to false.

Returns a success tuple with the file in the new destination like: {:ok, %Dropkick.File{}}.

@callback delete(Dropkick.File.t(), Keyword.t()) ::
  {:ok, Dropkick.File.t()} | {:error, String.t()}

Deletes the given file with the underlyning storage module. Returns a success tuple with the deleted the file like: {:ok, %Dropkick.File{}}.

@callback read(Dropkick.File.t(), Keyword.t()) :: {:ok, binary()} | {:error, String.t()}

Reads the given file with the underlyning storage module. Returns a success tuple with the content of the file like: {:ok, content}.

@callback store(Dropkick.File.t(), Keyword.t()) ::
  {:ok, Dropkick.File.t()} | {:error, String.t()}

Stores the given file with the underlyning storage module. The underlyning implementation should accept the following options (besides any specific options):

• :folder: The base location where to save the file being transfered.
• :prefix: A sub-folder inside the current location where the file is going to be saved, defaults to /.

Returns a success tuple like: {:ok, %Dropkick.File{}}.