Add tests

tests/init.lua

@@ -0,0 +1,11 @@
+local plenary_dir = os.getenv("PLENARY_DIR") or "/tmp/plenary.nvim"
+local is_not_a_directory = vim.fn.isdirectory(plenary_dir) == 0
+if is_not_a_directory then
+  vim.fn.system({ "git", "clone", "https://github.com/nvim-lua/plenary.nvim", plenary_dir })
+end
+
+vim.opt.rtp:append(".")
+vim.opt.rtp:append(plenary_dir)
+
+vim.cmd("runtime plugin/plenary.vim")
+require("plenary.busted")