gather_() will likely become defunct in tidyr 1.2.0 #2088Description
We are planning on moving the lazyeval versions of the main tidyr verbs to the defunct stage in the next version of tidyr. They have been deprecated for awhile now, and the NSE versions can do everything the lazyeval versions were meant to help with. See tidyverse/tidyr#1281 for more information.
Could you please remove your usage of gather_() from plotly?