Feature Request: have ActivityWorker provide a list of installed handlers

[pkrull]

It would be nice, particularly for unit testing, if ActivityWorker could provide a list of installed handlers. The returned list could simply contain the activity names.

[sclasen]

@pkrull seems reasonable, fancy trying your hand at a PR?

[pkrull]

@sclasen You flatter me. I'm a go newbie but could probably tackle it. I might be able to get to it within the next week or so. Do you have a preference for the function name?

[sclasen]

:)

Maybe just make it func Handers() map[string]*ActivityHandler and return a copy of the handlers map?