Document "manage.py smtpd" in README, fixes #188
Document "manage.py smtpd" in README, fixes #188

iphoting/healthchecks,healthchecks/healthchecks,healthchecks/healthchecks,iphoting/healthchecks,healthchecks/healthchecks,healthchecks/healthchecks,iphoting/healthchecks,iphoting/healthchecks