connect after event handlers are added, fix tests

[calvinfo]

This commit introduces several changes

• fixes tests by randomizing topic names
• bumps the circle nsq version
• adds reader connection post after construction

This last bullet allows the reader to add event handlers before the connection is made.

[calvinfo]

The reason the tests are flakey with a single topic name is that I'm pretty sure the nsqlookups don't atomically delete the topic over the course of the request. It's quick enough on the local machine, but on circle it makes for a much flakier set of tests.

[juliangruber]

maybe i missed it in the diff, but can you add a test for "adds reader connection post after construction"?

[calvinfo]

@juliangruber, good call–done!

[gjohnson]

LGTM!

[calvinfo]

thanks guys!