fix tests

tests/testthat/test-clipboard.R

@@ -1,9 +1,11 @@
 context("clipboard.R")
 
 test_that("clipboard works", {
-  # why is the <<- needed? Won't work without it...
-  t1 <<- AMR::antibiotics
-  clipboard_export(t1, info = FALSE)
-  t2 <- clipboard_import()
-  expect_equal(t1, t2)
+  if (Sys.info()['sysname'] == "Windows") {
+    # why is the <<- needed? Won't work without it...
+    t1 <<- AMR::antibiotics
+    clipboard_export(t1, info = FALSE)
+    t2 <- clipboard_import()
+    expect_equal(t1, t2)
+  }
 })