Properly respond to a modified manifest file

[dominicbarnes]

Currently, if you change a version in your manifest file, it will only update the dependency when you:

• clean the duo cache
• remove components
• touch/modify your files (and then, only the modified files get the updated version)

This causes headaches when using a manifest for managing versions in your project, because only the first 2 options end up being viable in practice. Not only that, but in a CI environment, you can't reliably cache the components directory, because it will not remain up-to-date for the same reasons.

This changes the internal behavior and makes a modified manifest invalidate the cache for individual files. (causing it to re-resolve the dependencies) A lot of the caching work I've been doing makes this a reliable action to take. (and will hit the API far fewer times than having to re-resolve everything after destroying the cache)

[stephenmathieson]

lgtm!

[dominicbarnes]

Sweet! I'm going to make one other PR sometime today in this same vein. It should be the last piece to efficiently using Duo in CI. :)

[stephenmathieson]

awesome!