Update OpenTSDB documentation (2.3.0)

lib/docs/scrapers/opentsdb.rb

@@ -2,7 +2,7 @@ module Docs
   class Opentsdb < UrlScraper
     self.name = 'OpenTSDB'
     self.type = 'sphinx_simple'
-    self.release = '2.2.1'
+    self.release = '2.3.0'
     self.base_url = 'http://opentsdb.net/docs/build/html/'
     self.root_path = 'index.html'
     self.links = {