gnu: r-ggplot2: Update to 3.0.0

* gnu/packages/statistics.scm (r-ggplot2): Update to 3.0.0
[propagated-inputs]: Add r-mgcv, r-rlang, r-viridislite, and r-withr.
[home-page]: Update URL.

Signed-off-by: Leo Famulari <leo@famulari.name>

gnu/packages/statistics.scm

@@ -1061,13 +1061,13 @@ legends.")
 (define-public r-ggplot2
   (package
     (name "r-ggplot2")
-    (version "2.2.1")
+    (version "3.0.0")
     (source
      (origin
        (method url-fetch)
        (uri (cran-uri "ggplot2" version))
        (sha256
-        (base32 "0543782ddv2hp6s0l702mnxfg8n7a6qlbm8bm55x22hnqgz8kg2z"))))
+        (base32 "0kb977hizsvk3b1k3zr717q78bpmbabhl8cj9a3w717nkq1zas67"))))
     (build-system r-build-system)
     (propagated-inputs
      `(("r-digest" ,r-digest)
@@ -1075,11 +1075,15 @@ legends.")
        ("r-plyr" ,r-plyr)
        ("r-lazyeval" ,r-lazyeval)
        ("r-mass" ,r-mass)
+       ("r-mgcv" ,r-mgcv)
        ("r-tibble" ,r-tibble)
        ("r-reshape2" ,r-reshape2)
+       ("r-rlang" ,r-rlang)
        ("r-scales" ,r-scales)
-       ("r-svglite" ,r-svglite))) ; Needed for 'ggsave'
-    (home-page "http://ggplot2.org")
+       ("r-svglite" ,r-svglite) ; Needed for 'ggsave'
+       ("r-viridislite" ,r-viridislite)
+       ("r-withr" ,r-withr)))
+    (home-page "https://ggplot2.tidyverse.org")
     (synopsis "An implementation of the grammar of graphics")
     (description
      "Ggplot2 is an implementation of the grammar of graphics in R.  It