Merge pull request #44 from benoitf/patch-1

Add link to execute the guide in a browser IDE (using Codenvy)

README.adoc

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+image:http://beta.codenvy.com/factory/resources/codenvy-contribute.svg["Codenvy Developer Workspace", link="http://beta.codenvy.com/f?id=9fq0busbm3tz7i8c"]
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 This guide walks you through the process of creating a "hello world" link:/understanding/REST[RESTful web service] with Spring.
 
 == What you'll build