Switch to py.test assertions.
Switch to py.test assertions.

mhils/pyopenssl,mitghi/pyopenssl,hynek/pyopenssl,aalba6675/pyopenssl,aalba6675/pyopenssl,hynek/pyopenssl,r0ro/pyopenssl,pyca/pyopenssl,reaperhulk/pyopenssl,mitghi/pyopenssl,r0ro/pyopenssl,reaperhulk/pyopenssl,mhils/pyopenssl