Use mineprefs in Pivotal-Preferences-RubyMine to generate directories

Per @moonmaster9000 we've made the Pivotal-Preferences-RubyMine mineprefs script create the necessary directories for installing RubyMine preferences, pending https://github.com/pivotal/Pivotal-Preferences-RubyMine/pull/27.  This PR would move all the preferences behavior previously in this recipe to the mineprefs script.