gg_subseries() incorrectly uses lubridate::floor_date()

[mitchelloharawild]

Seasonalities can be misaligned due to incorrectly assuming that these two calls give the same result:

library(lubridate)
#> 
#> Attaching package: 'lubridate'
#> The following object is masked from 'package:base':
#> 
#>     date
floor_date(ymd("2011-01-29"), "week")
#> [1] "2011-01-23"
floor_date(ymd("2011-01-29"), days(7))
#> [1] "2011-01-29"

^{Created on 2020-03-04 by the reprex package (v0.3.0)}