SEO: title and logo (#85)

Don't override title
Add SVG logo to all pages

Author: arcivanov

_config.yml

@@ -33,3 +33,4 @@ exclude:
 twitter:
   card: summary
   username: pybuilder_
+logo: /img/logo.svg

_includes/layout/metaAndStyles.html

@@ -30,4 +30,4 @@
 <link rel="stylesheet" type="text/css" href="/css/tabcontent.css"/>
 <link rel="stylesheet" type="text/css" href="/css/styles.css"/>
 
-{% seo %}
+{% seo title=false %}