Update CONTRIBUTING.md (#2417)

CLA url is no long valid. Updated the link and tweaked the instructions.
2018-04-11 02:12:42 -05:00 · 2018-04-11 02:12:42 -05:00 · 6376fe7bf2
--- a/CONTRIBUTING.md
+++ b/CONTRIBUTING.md
@ -8,7 +8,7 @@ Please see our [Code of Conduct](CODE_OF_CONDUCT.md).

 ## Prerequisite

-You will need to complete a Contribution License Agreement before any pull request can be accepted. Complete the CLA at https://cla2.dotnetfoundation.org/.
+You will need to complete a Contribution License Agreement before any pull request can be accepted. Review the CLA at https://cla.dotnetfoundation.org/. When you submit a pull request, a CLA assistant bot will confirm you have completed the agreement, or provide you with an opportunitiy to do so.

 ## Contributing Code