Add support for server minimongo

[vbgm]

When trying to publish from server-only minimongo, following error is shown:

TypeError: Cannot read property 'selector' of undefined
at HandlerController.add (packages/cottz:publish-relations/lib/server/handler_controller.js:22:34)
at CursorMethods.cursor (packages/cottz:publish-relations/lib/server/cursor/cursor.js:20:34)

[lfades]

Maybe at some point the internal implementation of minimongo changed and this line may have broke.

[vbgm]

I guess there are no plans to fix this? :-)

[lfades]

Yeah, sorry about that.

I'm not working with Meteor anymore, and even If I come back because I still think Meteor is great, I'll use Apollo Graphql instead of publish/subscribe.