Update means to sign Pivotal CLA

CONTRIBUTING.adoc

@@ -18,13 +18,13 @@ If you are reporting a bug, please help to speed up problem diagnosis by providi
 information as possible. Submitting a github-hosted sample project replicating the problem helps.
 
 == Sign the Contributor License Agreement
-Before we accept a non-trivial patch or pull request we will need you to sign the
-https://support.springsource.com/spring_committer_signup[contributor's agreement].
+If you have not previously done so, please fill out and
+submit the https://cla.pivotal.io/sign/spring[Contributor License Agreement].
+
 Signing the contributor's agreement does not grant anyone commit rights to the main
 repository, but it does mean that we can accept your contributions, and you will get an
 author credit if we do.  Active contributors might be asked to join the core team, and
-given the ability to merge pull requests. Use '`Phillip Webb`' or '`Dave Syer`' in the
-project lead field when you complete the form.
+given the ability to merge pull requests.
 
 == Code Conventions and Housekeeping
 None of these are essential for a pull request, but they help.  They can also be