--notest for particular dependencies

[davidcantrell-bb]

When installing the zillion dependencies for my application, two of them, Foo::Bar and Baz::Barf, have known test failures which I don't care about. It would be handy to be able to tell cpanm to test and install all the dependencies, including the dependencies of Foo::Bar and Baz::Barf, but to skip tests for Foo::Bar and Baz::Barf only.

I suggest a command-line syntax like --notest=Foo::Bar,Baz::Barf,....