linting of TS-invalid repository name should raise error

[martenson]

We just had a case (repo name apCLMS_to_RamClustR_converter) where the CI passes fine but the toolshed upload fails (silently)

Unexpected HTTP status code: 400: {"err_msg": "Repository names must contain only lower-case letters, numbers and underscore.", "err_code": 400008}

[bernt-matthias]

I think this should be part of planemo lint or shed_lint.

[bernt-matthias]

shed_lint reports

.. WARNING: Repository name [apCLMS_to_RamClustR_converter] invalid. Repository names must contain only lower-case letters, numbers and underscore.

Since we call shed_lint with --report_level warn --fail_level error this "error" is missed.

I guess we should change this to error since using --fail_level warn would catch to many cases.

In addition I think it would be nice to make users more aware of these warnings.