Add really basic test

Author: pynappo

tests/neo-tree/utils/fs_spec.lua

@@ -0,0 +1,10 @@
+pcall(require, "luacov")
+local utils = require("neo-tree.utils")
+
+describe("fs_parent", function()
+  it("works", function()
+    assert.are.same(nil, utils.fs_parent("/"))
+    assert.are.same("/", utils.fs_parent("/foo"))
+    assert.are.same("/", utils.fs_parent("/foo/bar", true))
+  end)
+end)