plotting vertical limes doesn't work

[RobWHickman]

I needed to added a vertical line to a plot but the following codes gives an error

'Error in geom_vlime(x_intercept = 0.5) : could not find function "geom_vlime"'

reproducible example:

library(ggplot2)

date <- data.frame(
  x = runif(100),
  y = runif(100)
)

p <- ggplot(date, aes(x, y)) +
  geom_point()
  geom_vlime(x_intercept = 0.5) +
  theme_mimimal()

I'll make a pull request to fix this tomorrow