Bump testthat and R versions

Author: ateucher

DESCRIPTION

@@ -20,7 +20,7 @@ License: MIT + file LICENSE
 URL: https://usethis.r-lib.org, https://github.com/r-lib/usethis
 BugReports: https://github.com/r-lib/usethis/issues
 Depends: 
-    R (>= 3.4)
+    R (>= 3.6)
 Imports: 
     cli (>= 3.0.1),
     clipr (>= 0.3.0),
@@ -52,12 +52,10 @@ Suggests:
     roxygen2 (>= 7.1.2),
     spelling (>= 1.2),
     styler (>= 1.2.0),
-    testthat (>= 3.1.7.9000)
+    testthat (>= 3.1.8)
 Config/Needs/website: tidyverse/tidytemplate, xml2
 Config/testthat/edition: 3
 Encoding: UTF-8
 Language: en-US
 Roxygen: list(markdown = TRUE)
 RoxygenNote: 7.2.3
-Remotes:  
-    r-lib/testthat