Added new test to cookies spec to cover bug on cookies banner and fixed it. See issue #2599.

Also, improved readability on cookies spec with some extracted methods.

app/assets/javascripts/darkswarm/cookies_banner/cookies_banner_controller.js.coffee

@@ -3,3 +3,4 @@ Darkswarm.controller "CookiesBannerCtrl", ($scope, CookiesBannerService, $http,
   $scope.acceptCookies = ->
     $http.post('/api/cookies/consent')
     CookiesBannerService.close()
+    CookiesBannerService.disable()

app/assets/javascripts/darkswarm/cookies_banner/cookies_banner_directive.js.coffee

@@ -2,5 +2,5 @@ Darkswarm.directive 'cookiesBanner', (CookiesBannerService) ->
   restrict: 'A'
   link: (scope, elm, attr)->
     return if not attr.cookiesBanner? || attr.cookiesBanner == 'false'
-    CookiesBannerService.setActive()
+    CookiesBannerService.enable()
     CookiesBannerService.open()

app/assets/javascripts/darkswarm/cookies_banner/cookies_banner_service.js.coffee

@@ -2,10 +2,10 @@ Darkswarm.factory "CookiesBannerService", (Navigation, $modal, $location, Redire
 
   new class CookiesBannerService
     modalMessage: null
-    isActive: false
+    isEnabled: false
 
     open: (path, template = 'darkswarm/cookies_banner/cookies_banner.html') =>
-      return unless @isActive
+      return unless @isEnabled
       @modalInstance = $modal.open
         templateUrl: template
         windowClass: "cookies-banner full"
@@ -13,8 +13,11 @@ Darkswarm.factory "CookiesBannerService", (Navigation, $modal, $location, Redire
         keyboard: false
 
     close: =>
-      return unless @isActive
+      return unless @isEnabled
       @modalInstance.close()
 
-    setActive: =>
-      @isActive = true
+    enable: =>
+      @isEnabled = true
+
+    disable: =>
+      @isEnabled = false