tests/sitecustomize.py

sshpeer: add implementation of _calltwowaystream

This implements the call needed by bundle2. The error handling is a bit flaky
right now, but bundle2 error handling in general is still flaky anyway. Bundle2
is still disabled by default, I do not expect this to be a problem.

try:
    import coverage
    getattr(coverage, 'process_startup', lambda: None)()
except ImportError:
    pass