Fix missing start end times in execution inspect

zoe_api/web/templates/execution_inspect.html

 {% extends "base_user.html" %}
 {% block title %}Inspect execution {{ e.name }}{% endblock %}
+
+{% block custom_head %}
+    <script src="/static/moment.min.js" type="application/javascript"></script>
+    <script src="/static/moment-timezone.min.js" type="application/javascript"></script>
+    <script>
+    function format_timestamp(ts) {
+        var m = moment.utc(ts);
+        m.local();
+        document.write(m.calendar());
+    }
+    </script>
+{% endblock %}
+
 {% block content %}
 <h1>Zoe - Analytics on demand</h1>
 <h2>Detailed information for execution {{ e.name }}</h2>