Add test file with a doppelganger-test

Author: Thomas Knecht

tests/testthat/test-position-nudgestack.R

@@ -110,4 +110,3 @@ test_that("position_nudgestack() can stack correctly when ymax is NA", {
     geom_point(position = position_nudgestack(x = 0.5))
   expect_equal(layer_data(p)$y, c(1, 2))
 })
-