Proposal: Lock module version in lookup.json

As we test more modules in CitGM, triaging failures does not seem to be scaling.

With any failure we need to work out whether it was caused by:

• the change in Node we're testing
• the module/module test suite being updated
• flaky tests

To make life easier I would suggest that we:

• Lock the modules to specific (known working) versions in the lookup.json (with appropriate flaky tags if necessary).
• Allow module authors to raise PRs to update the versions (when they feel like it). We can update modules ourselves in batches too (perhaps at weekly or monthly intervals).

This means that instead of constantly having to stay on top of all of the module/modules test suite updates and regularly having to mark some of these tests as flaky, we could do this in batches at a regular interval.