aes_string is deprecated

[richardjtelford]

plotDensityClust uses aes_string which was deprecated in ggplot2 v3.0

library(densityClust)
data.dist <- dist(iris[, 1:4])


# Run initial density clustering
dens.clust <- densityClust(data.dist)
#> Distance cutoff calculated to 0.2767655
plotDensityClust(dens.clust, type = "dg")
#> Warning: `aes_string()` was deprecated in ggplot2 3.0.0.
#> ℹ Please use tidy evaluation idioms with `aes()`.
#> ℹ See also `vignette("ggplot2-in-packages")` for more information.
#> ℹ The deprecated feature was likely used in the densityClust package.
#>   Please report the issue at
#>   <https://github.com/thomasp85/densityClust/issues>.
#> This warning is displayed once per session.
#> Call `lifecycle::last_lifecycle_warnings()` to see where this warning was
#> generated.
#> Ignoring unknown labels:
#> • colour : "Cluster"

I can send a pull request fixing this if you would like me to