* All the API functions are stubbed out, now they just need to be filled in
  with details, so they actually do what they are supposed to.
* Need to make sure the correct errors are getting returned.
* Need to back through and fix all occurences of the `Metadata` type to be what
  it is actually supposed to be. Here are all the `Metadata` types I have
  encountered so far:

    * FileMetadata
    * FolderMetadata
    * PathLinkMetadata
    * SharedFolderMetadata
    * LinkMetadata
    * more?