Can we drop warning advice from last_warnings()?

[hadley]

Instead of:

message: `data_frame()` is deprecated as of tibble 1.1.0.
Please use `tibble()` instead.
This warning is displayed once every 8 hours.
Call `lifecycle::last_warnings()` to see where this warning was generated.
backtrace:

Could we show:

<deprecated>
message: `data_frame()` is deprecated as of tibble 1.1.0.
Please use `tibble()` instead.
backtrace:

?

(Also note that backtrace should get a capital letter and should be bolded to match last_trace())