Use TestRunner from FrameworkTest
Create ShellUtils class, use inside of TestRunner

The only reason to separate out ShellUtils is so setup.py
files can quickly use this new utility code without having to transition
over to being a subclass of TestRunner first. I don't think that transition
it hard at all, but I haven't looked at every setup.py, so I want to make
the process as easy as possible
Make go's setup.py a subclass of TestRunner (and use new shell utility code)
Documentation for WrapLogger