REDO: bug908331 - fixed events-guide URL https://github.com/mozilla/webmaker-events/commit/a892edb51a5cedb17562fe7ca1c1304e4f36a23b
REDO Bug 909736 - Update webmaker-postalservice to v0.2.3 - https://github.com/mozilla/webmaker-events/commit/0365982d23374dca9f2735df350d269eb0e5e503
REDO    Fix bug 911239 - Only send event creation email to users when they permit it https://github.com/mozilla/webmaker-events/commit/16900055a0b0ed198f6828a616d1349945b938fa