Default foobara's minimum to the current version of foobara

Currently we do `[">= 0.0.136", "< 2.0.0"]` but I assume we could find the currently used version of Foobara in memory and use that instead and I wonder if we can use `"~> #{current_foobara_version_or_whatever}"` but not sure if `~>` does minor or major version. I suppose minor and I think pre-release we can just stick with the two entry form. That's probably why I didn't use `~>`

Locate the generator code containing the existing [">= 0.0.136", "< 2.0.0"] constraint and inspect how the current Foobara version is available. Done means generated Ruby projects default to the current Foobara version while prerelease handling preserves the two-entry constraint form.

Written by the indexing model from the issue text.