chore: drop the CLA links

Author: Sam Harrison

README.rst

@@ -110,7 +110,6 @@ Quick links:
 
 -  `Feature Request`_
 -  `Bug Reports`_
--  `Sign the CLA to Create a Pull Request`_
 -  `Improvements to the Codebase`_
 -  `Review Pull Requests`_
 
@@ -155,7 +154,6 @@ License
 .. _CONTRIBUTING: https://github.com/sendgrid/python-http-client/blob/master/CONTRIBUTING.md
 .. _Feature Request: https://github.com/sendgrid/python-http-client/blob/master/CONTRIBUTING.md#feature-request
 .. _Bug Reports: https://github.com/sendgrid/python-http-client/blob/master/CONTRIBUTING.md#submit-a-bug-report
-.. _Sign the CLA to Create a Pull Request: https://github.com/sendgrid/python-http-client/blob/master/CONTRIBUTING.md#cla
 .. _Improvements to the Codebase: https://github.com/sendgrid/python-http-client/blob/master/CONTRIBUTING.md#improvements-to-the-codebase
 .. _Review Pull Requests: https://github.com/sendgrid/python-http-client/blob/master/CONTRIBUTING.md#code-reviews
 .. _troubleshooting guide: https://github.com/sendgrid/python-http-client/blob/master/TROUBLESHOOTING.md