Migrate away from event-stream package

[andylolz]

event-stream is no longer maintained, and has some issues. I’ve pinned to the last version without security issues, but it would be preferable to use an alternative.

[rufuspollock]

@andylolz great suggestion. Are you up for doing some work on this?

[andylolz]

Hi @rufuspollock, apologies for the delayed response! Yes sure, I’ll take a look this weekend.

[rufuspollock]

@andylolz awesome - let me know how this goes.