Better handling of linetype for bar-like traces

For one, it should map to marker.line.dash instead of line.dash. Also, the value shouldn't be added to the trace name

zoo_dat <- tibble::tibble(
  animal = rep(c('giraffes', 'orangutans', 'monkeys'), 2),
  count = c(20, 14, 23, 12, 18, 29),
  zoo = rep(c('SF Zoo', 'LA Zoo'), each = 3)
)
plot_ly(zoo_dat) %>%
  add_bars(
    x = ~animal,
    y = ~count,
    color = ~zoo,
    stroke = I("black"),
    linetype = I(5)
  )

Start by reproducing the supplied plot_ly() and add_bars() example in the plotly.R repository, then trace how bar-like traces process linetype. Confirm the generated mapping and trace name against the issue's expected behavior; done means the example uses marker.line.dash and does not append the linetype value to the trace name.