Fix restaurant endpoitns to support slugs as ids

[L8D]

This would require replacing all the dirac calls with controller methods (at least all the reads)

[jrf0110]

If you wanted to continue using dirac-middleware, some simple middleware could support slugs:

module.exports = ( options )=>{
  options = utils.defaults( options || {}, {
    idParam: 'id'
  });

  return ( req, res, next )=>{
    var id = req.params[ options.idParam ];

    if ( isNaN( +id ) ){
      req.queryObj.text_id = id;
    } else {
      req.queryObj.id = id;
    }

    return next();
  };
};

Or you could just use the .getRestaurant() middleware to fetch the restaurant, which already supports fetching by slug

[jrf0110]

And of course, that could be generalized further