Fixed broken example

[genya0407]

If we pass Symbol as map's second argument, we get following exception.

can't convert Symbol to Integer (TypeError)

It seems that we cannot use Symbol, and should use Integer (maybe we could in the past?).

• https://github.com/katzer/mruby-shelf/blob/master/mrblib/shelf/builder.rb#L159
• https://github.com/katzer/mruby-r3/blob/master/mrblib/r3.rb#L46

So I fixed the example to use get method, instead of using map .

[katzer]

yes, it should be an int like R3::GET instead of :GET

[katzer]

thanks!