Update FontAwesome (#83)

layouts/_default/baseof.html

@@ -15,7 +15,7 @@
     <link rel="canonical" href="{{ .Permalink }}">
 
     <link href="https://fonts.googleapis.com/css?family=Lato:400,700|Merriweather:300,700|Source+Code+Pro:400,700" rel="stylesheet">
-    <link rel="stylesheet" href="https://use.fontawesome.com/releases/v5.2.0/css/all.css" integrity="sha384-hWVjflwFxL6sNzntih27bfxkr27PmbbK/iSvJ+a4+0owXq79v+lsFkW54bOGbiDQ" crossorigin="anonymous" />
+    <link rel="stylesheet" href="https://use.fontawesome.com/releases/v5.3.1/css/all.css" integrity="sha384-mzrmE5qonljUremFsqc01SB46JvROS7bZs3IO2EmfFsd15uHvIt+Y8vEf7N7fWAU" crossorigin="anonymous" />
     <link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/normalize/8.0.0/normalize.min.css" integrity="sha256-oSrCnRYXvHG31SBifqP2PM1uje7SJUyX0nTwO2RJV54=" crossorigin="anonymous" />
 
     {{ if .Site.IsServer }}