add support for googlebot detection

src/bowser.js

@@ -142,6 +142,13 @@
       , version: versionIdentifier
       }
     }
+    else if(/googlebot/i.test(ua)) {
+      result = {
+        name: 'Googlebot'
+      , googlebot: t
+      , version: getFirstMatch(/googlebot\/(\d+(\.\d+))/i) || versionIdentifier
+      }
+    }
     else result = {}
 
     // set webkit or gecko flag for browsers based on these engines

src/useragents.js

@@ -931,4 +931,11 @@ module.exports.useragents = {
       , x: true
       }
     }
+  , Googlebot: {
+    'Mozilla/5.0 (compatible; Googlebot/2.1; +http://www.google.com/bot.html)': {
+      googlebot: true
+    , version: '2.1'
+    , x: true
+    }
+  }
 };