https://jira.mongodb.org/browse/RUBY-1384 documented start_transaction as taking after_cluster_time as a read concern option, but this is not correct: after cluster time is not a user-specifiable option at all.

"Read concern" is peculiar in that the term refers to two different things: options passable by the user (which has only one sub-option, level) and document passed by the driver to the server (which can additionally have afterClusterTime, which is not user specifiable).

This ticket proposes to add a verifier to the linter to ensure that methods that accept a read concern are passed only the user options variety of the read concern.