New install_strategy primarily to help reduce test-kitchen run times in some scenarios.

Describe the Enhancement:

I would like an install strategy of 'version' or whatever word makes most sense. As an example, for the Chef product.....the following actions would be expected for each version setting
14 -> if latest 14 is not installed, install latest 14.x.x
14.12 -> if latest 14.12 is not installed, install latest 14.12.x
14.14.14 -> if this exact version is not installed, install 14.14.14

Describe the Need:

From personal experience, the need is for a test-kitchen situations where the user

1. has to deal with Chef baked into an image
2. desires a different version of Chef to be tested with, perhaps as different set of suites for example
3. would reduce testing times by not having to download/install a version every time using the :always workaround

Current Alternative

Use the :always strategy, which is lots of extra work for scenarios involving one or more restarts and a good number of test suites.

Can We Help You Implement This?:

I can take a stab at this, but the going may be relatively slow as compared to someone who knows the code base very well.

Start by tracing the existing :always install strategy and the entry points that select and resolve install versions. Define the new strategy's behavior for major, minor, and exact Chef versions, then verify that already-installed matching versions are reused and missing versions are installed.