gnu: Add r-packrat.

* gnu/packages/cran.scm (r-packrat): New variable.

gnu/packages/cran.scm

@@ -20238,3 +20238,24 @@ (define-public r-iheatmapr
 providing tooltips with information about each cell and enabling zooming into
 interesting features. iheatmapr uses the plotly library for interactivity.")
     (license license:expat)))
+
+(define-public r-packrat
+  (package
+    (name "r-packrat")
+    (version "0.5.0")
+    (source
+     (origin
+       (method url-fetch)
+       (uri (cran-uri "packrat" version))
+       (sha256
+        (base32
+         "1xy5dd2hrpqa07jfl4s7dsrya05mf36ms74j833scdz0zf89586n"))))
+    (properties `((upstream-name . "packrat")))
+    (build-system r-build-system)
+    (home-page "https://github.com/rstudio/packrat/")
+    (synopsis "Dependency management R projects")
+    (description
+     "This package provides a dependency manager for R projects that allows
+you to manage the R packages your project depends on in an isolated, portable,
+and reproducible way.")
+    (license license:gpl2)))