use verbs "revoke" and "grant"

[leslie-corbalt]

PR Description

This PR, in terms of roles, uses the verb "Revoke" instead of "Drop" and "Grant" instead of "Add".
In SQL, Drop has a different meaning from Revoke, and the SQL command is REVOKE, not DROP.
Add has a different meaning from Grant, and the SQL command is GRANT, not ADD.

PR Checklist

• New automated tests have been written to the extent possible.
• The code has been checked for structural/syntactic validity.
  • AMI/application: a build was performed
  • terraform changes: "terraform plan" checked on every affected environment
• (If applicable) the code has been manually tested on our infrastructure.
  • AMI/application: deployed an a test or dev environment
  • terraform changes: applied to test or dev environment
  • script: run against test or dev environment
• Likely failure points and new functionality have been identified and tested manually.
  Examples:
  • Application manually run in a way that triggers any new branches
  • AMI logged into and changes verified from login shell
• Pull request description includes a description of all the manual steps performed to accomplish the above.

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[hundt-corbalt]

LGTM! Good idea to clarify

[leslie-corbalt]

#12