[ruby/uri] Bump up 0.13.1

https://github.com/ruby/uri/commit/31ec9cea66

lib/uri/version.rb

@@ -1,6 +1,6 @@
 module URI
   # :stopdoc:
-  VERSION_CODE = '001300'.freeze
+  VERSION_CODE = '001301'.freeze
   VERSION = VERSION_CODE.scan(/../).collect{|n| n.to_i}.join('.').freeze
   # :startdoc:
 end