v1.1.0 release candidate

[cbraynor]

Changes the constructor to return an actual Queue object instead of a promise (which was weird, this is much more idiomatic), and adds a shutdown() method to the returned object that gracefully shuts down all workers before resolving the promise that it returns (as per #13). This technically changes how the constructor behaves, but I doubt anyone's using the (undocumented) promise it used to return, so I think just a minor version bump is right

/cc @mcdonamp

[coveralls]

Coverage remained the same at 100.0% when pulling fe6bc60c36092d1883dfe426cb2779fd22232557 on 1-1-0 into 7c3225c6216907a93220e4132f27cfbd0e246090 on master.

[coveralls]

Coverage remained the same at 100.0% when pulling 1a96bf43b4cf3858615228ae8176e91958206bb4 on 1-1-0 into 7c3225c6216907a93220e4132f27cfbd0e246090 on master.

[m-tse]

looks good, nice work Chris.

[dusty]

Thanks!