Install ox-hugo directly from GitHub source code

ox-hugo (github link) is a fantastic package that can help transform org-mode notes into HUGO blog posts. The installation is very easy if you use vanilla Emacs (i.e. just use MELPA). However, on the current develop branch of Spacemacs, I encountered the problem of dependency mismatch where ox-hugo requires org package while Spacemacs uses org-plus-contrib package. As a result, on starting Spacemacs it will try to delete org package and the reinstall org after it tries to load ox-hugo.