Add commands to create event/events

[fghibellini]

Ideally in the multiple event case we want to be able to stream a sequence of values into the program and on each parse perform a request to Event Store so that it works nicely with linux piping.

• create single event passed as argument
• create single event & read data from stdin
• create multiple events from stdin
• json vs binary data
• add --interractive | -i flag

add-event -i behaviour

#!/usr/bin/env bash
TMPFILE="$(mktemp /tmp/event-store-event.XXXXXX)"
event-store-ctl send-event --output-template > "$TMPFILE"
$EDITOR "$TMPFILE"
event-store-ctl send-event < "$TMPFILE"
rm "$TMPFILE"