Compare like values in find_bundler

The input to this method is not guaranteed to be a string, it could be a `Gem::Version` this normalizes the comparison.

Author: lolwut

bundler/lib/bundler/rubygems_integration.rb

@@ -432,7 +432,7 @@ def default_specs
     end
 
     def find_bundler(version)
-      find_name("bundler").find {|s| s.version.to_s == version }
+      find_name("bundler").find {|s| s.version.to_s == version.to_s }
     end
 
     def find_name(name)