Resolve aes_string and size deprecation

[pdil]

aes_string

aes_string is soft-deprecated in ggplot2 according to https://ggplot2.tidyverse.org/reference/aes_.html, see warnings below.

══ Warnings ════════════════════════════════════════════════════════════════════
── Warning ('test-plot.R:10'): (code run outside of `test_that()`) ─────────────
Using `size` aesthetic for lines was deprecated in ggplot2 3.4.0.
ℹ Please use `linewidth` instead.
Backtrace:
 1. usmap::plot_usmap("counties", fill = "red")
      at test-plot.R:10:0
 3. ggplot2 (local) `<fn>`(fill = "red", color = "black", size = 0.4, mapping = `<uneval>`)
 4. ggplot2::layer(...)
 5. ggplot2:::deprecate_soft0(...)
── Warning ('test-plot.R:11'): (code run outside of `test_that()`) ─────────────
`aes_string()` was deprecated in ggplot2 3.0.0.
ℹ Please use tidy evaluation ideoms with `aes()`
Backtrace:
 1. usmap::plot_usmap(data = statepop, values = "pop_2015", color = "blue")
      at test-plot.R:11:0
 2. ggplot2::aes_string(x = "x", y = "y", group = "group", fill = values)
 3. ggplot2:::deprecate_soft0("3.0.0", "aes_string()", details = "Please use tidy evaluation ideoms with `aes()`")

size

size is deprecated in ggplot2 3.4.0 and has been replaced with linewidth

Plan

Fixes will be included in v0.6.1 release.