Updating CONTRIBUTING.md to reflect new CLA links (atlassian#240)

Author: ometelytsia

CONTRIBUTING.md

@@ -31,5 +31,5 @@ link below to digitally sign the CLA. The Corporate CLA is for those who are
 contributing as a member of an organization and the individual CLA is for
 those contributing as an individual.
 
-* [CLA for corporate contributors](https://na2.docusign.net/Member/PowerFormSigning.aspx?PowerFormId=e1c17c66-ca4d-4aab-a953-2c231af4a20b)
-* [CLA for individuals](https://na2.docusign.net/Member/PowerFormSigning.aspx?PowerFormId=3f94fbdc-2fbe-46ac-b14c-5d152700ae5d)
+* [CLA for corporate contributors](https://opensource.atlassian.com/corporate)
+* [CLA for individuals](https://opensource.atlassian.com/individual)