make sure all the dirs exist

Author: andyleclair

lib/mix/tasks/copy_static.ex

@@ -7,7 +7,10 @@ defmodule Mix.Tasks.CopyStatic do
   def run(_args) do
     Mix.shell().info([:green, "Copying static files"])
 
+    # Ignoring if these exist
     File.mkdir(@output_dir)
+    File.mkdir(@image_dir)
+    File.mkdir(@font_dir)
     File.cp_r!(@font_dir, Path.join([@output_dir, "assets", "fonts"]))
     File.cp_r!(@image_dir, Path.join([@output_dir, "assets", "images"]))
   end