Update .gitlab-ci.yml with infohub option

.gitlab-ci.yml

 variables:
     CUCUMBER_TAG:
       value: "tsa"
-      description: "Enter which tests to be execute. Other valid options are - 'cache', 'policy', 'signer', 'task', 'negative'."
+      description: "Enter which tests to be execute. Other valid options are - 'cache', 'infohub', 'policy', 'signer', 'task', 'negative'."
     BASE_URL:
       value: "https://gaiax.vereign.com/tsa"
       description: "Enter the environment on which the services are deployed."