Navigation: Unified cloud navigation

* Removed main drop down menu
* Added "My cloud" to user menu
* Attract/Flamenco is found under Production Tools menu
* Attract/Flamenco has the same navigation as its project

src/templates/projects_index_collection.pug

@@ -1,5 +1,5 @@
 | {% extends 'layout.html' %}
-| {% from '_macros/_navigation.html' import navigation_learn, navigation_homepage %}
+| {% from '_macros/_navigation.html' import navigation_homepage %}
 
 include ../../../pillar/src/templates/mixins/components
 
@@ -42,11 +42,7 @@ meta(name="twitter:image", content="{{ page_header_image }}")
 | {% endblock %}
 
 | {% block navigation_tabs %}
-| {% if title == 'open-projects' %}
 | {{ navigation_homepage(title) }}
-| {% else %}
-| {{ navigation_learn(title) }}
-| {% endif %}
 | {% endblock navigation_tabs %}
 
 | {% block body %}