Report libraries using different versions in the workspace

[tengstrand]

Help users identify libraries that have different versions in the workspace

Some users are fine with just a warning, while others want an easy way to check for inconsistent libraries both in their local development environment and on the CI server.

Suggested solution:

Add a :validations key in workspace.edn:

 :validations {:inconsistent-lib-versions {:type :warning
                                           :exclude []}}

The :type can be set to either :warning or :error.
Libraries that should not be validated are listed in :exclude.

If :inconsistent-lib-versions is specified, the tool will report warnings or errors (depending on :type) when two or more libraries are detected with mismatched versions in the check, info, and test commands, and returns an error code if an error (same behaviour as today).

Rows in the libs table that contain libraries with different versions are highlighted in yellow if :type is set to :warning, and in red if :type is set to :error.

[tengstrand]

Only the check command will detect inconsistencies (and return the error code if type is set to :error), not the libs command.

[tengstrand]

Please try this out in 0.3.30-SNAPSHOT 1 that has been merged to master.