linkedin and github link (#27)

* Ref #24 linkedin and github social link in author page and article page

-test case for that

- BaseTest added

* Ref #24 icon to link since linkedin and github is not present

* article color fix

templates/page.html

@@ -21,6 +21,8 @@
   {% else %}
     {% set selected_cover = SITEURL+"/"+HEADER_COVER %}
   {% endif %}
+{% elif article.color %}
+  {% set selected_color = article.color %}
 {% elif HEADER_COLOR %}
   {% set selected_color = HEADER_COLOR %}
 {% endif %}