bigrquery 1.4.2

• Sync up with the current release of gargle (1.4.0). Recently gargle
  introduced some changes around OAuth and bigrquery is syncing with up that:

  • bq_oauth_client() is a new function to replace the now-deprecated
    bq_oauth_app().
  • The new client argument of bq_auth_configure() replaces the
    now-deprecated client argument.
  • The documentation of bq_auth_configure() emphasizes that the preferred
    way to "bring your own OAuth client" is by providing the JSON downloaded
    from Google Developers Console.

• op_table.lazy_select_query() now returns a string instead of a list, which
  fixes an error seen when printing or using functions like head() or
  dplyr::glimpse() (@clente, #509).