[IMP] web_tour: add 'mobile' flag for steps in tours

We are not able to precise in which case a step should be executed.
We already have 'edition' and now we introduce 'mobile'.

undefined: Desktop + Mobile*
true:      Mobile* only
false:     Desktop only

*: Responsive (<= SM), see isMobile

addons/web_tour/static/src/js/tour_manager.js

@@ -2,6 +2,7 @@ odoo.define('web_tour.TourManager', function(require) {
 "use strict";
 
 var core = require('web.core');
+var config = require('web.config');
 var local_storage = require('web.local_storage');
 var mixins = require('web.mixins');
 var utils = require('web_tour.utils');
@@ -116,7 +117,8 @@ return core.Class.extend(mixins.EventDispatcherMixin, ServicesMixin, {
         return tour.wait_for.then((function () {
             tour.current_step = parseInt(local_storage.getItem(get_step_key(name))) || 0;
             tour.steps = _.filter(tour.steps, (function (step) {
-                return !step.edition || step.edition === this.edition;
+                return (!step.edition || step.edition === this.edition) &&
+                    (step.mobile === undefined || step.mobile === config.device.isMobile);
             }).bind(this));
 
             if (tour_is_consumed || tour.current_step >= tour.steps.length) {