Update Node.js documentation (9.1.0)

lib/docs/scrapers/node.rb

@@ -23,17 +23,22 @@ module Docs
     HTML
 
     version do
-      self.release = '8.8.1'
+      self.release = '9.1.0'
+      self.base_url = 'https://nodejs.org/dist/latest-v9.x/docs/api/'
+    end
+
+    version '8 LTS' do
+      self.release = '8.9.1'
       self.base_url = 'https://nodejs.org/dist/latest-v8.x/docs/api/'
     end
 
     version '6 LTS' do
-      self.release = '6.11.5'
+      self.release = '6.12.0'
       self.base_url = 'https://nodejs.org/dist/latest-v6.x/docs/api/'
     end
 
     version '4 LTS' do
-      self.release = '4.8.5'
+      self.release = '4.8.6'
       self.base_url = 'https://nodejs.org/dist/latest-v4.x/docs/api/'
     end
   end