Added inventory page along with a navbar link.

Added inventory page showing a table similar to the "Nodes" one,
but containing any customizable set of facts.

A setting INVENTORY_FACTS has been added. It controls the list
of facts to be displayed along with a description for the header
of the table.

puppetboard/templates/inventory.html

@@ -0,0 +1,37 @@
+{% extends 'layout.html' %}
+{% block content %}
+<div class="alert alert-info">
+  PuppetDB currently only returns active nodes.
+</div>
+      {% with messages = get_flashed_messages(with_categories=true) %}
+      {% if messages %}
+      {% for category, message in messages %}
+        <div class="alert alert-{{category}}">
+          {{message}}
+        </div>
+      {% endfor %}
+      {% endif %}
+      {% endwith %}
+<div class="hide" style="margin-bottom:20px">
+<input autofocus="autofocus" style="width:100%" type="text" class="filter-table input-medium search-query" placeholder="Type here to filter">
+</div>
+<table class='inventory table table-striped table-condensed'>
+  <thead>
+    <tr>
+      {% for description in fact_desc %}
+      <th>{{description}}</th>
+      {% endfor %}
+    </tr>
+  </thead>
+  <tbody class="searchable">
+    {% for nodename in nodedata %}
+    <tr>
+ 
+      {% for item in nodedata[nodename] %}
+      <td>{{item}}</td>
+      {% endfor %}
+    </tr>
+    {% endfor %}
+  </tbody>
+</table>
+{% endblock content %}

puppetboard/templates/layout.html

@@ -33,6 +33,7 @@
       ('facts', 'Facts'),
       ('reports', 'Reports'),
       ('metrics', 'Metrics'),
+      ('inventory', 'Inventory'),
       ('query', 'Query'),
       ] %}
       <a {% if endpoint == request.endpoint %} class="active item" {% else %} class="item" {% endif %}