Add tests

and fix few mistakes

src/Wallabag/CoreBundle/Resources/views/Entry/entries.xml.twig

@@ -17,11 +17,11 @@
                 <pubDate>{{ entry.createdAt|date('D, d M Y H:i:s') }}</pubDate>
                 <description>
                     <![CDATA[
-                    {%- if entry.content| readingTime > 0 %}
+                    {%- if entry.content| readingTime > 0 -%}
                         {% trans %}estimated reading time :{% endtrans %} {{ entry.content| readingTime }} min
-                    {% else -%}
+                    {%- else -%}
                         {% trans %}estimated reading time :{% endtrans %} &lt; 1 min
-                    {% endif -%}
+                    {%- endif %}
 
                     {{ entry.content -}}
                     ]]>