tests: Test the place container.

tests/examples/wibox/container/defaults/place.lua

@@ -0,0 +1,24 @@
+--DOC_HIDE_ALL
+local wibox     = require("wibox")
+
+return {
+    text   = "Before",
+    align  = "center",
+    valign = "center",
+    widget = wibox.widget.textbox,
+},
+{
+    {
+        {
+            text   = "After",
+            align  = "center",
+            valign = "center",
+            widget = wibox.widget.textbox,
+        },
+        valign = "bottom",
+        halign = "right",
+        widget = wibox.container.place
+    },
+    margins = 5,
+    layout = wibox.container.margin
+}