* Pool.query calls cb if connect() fails
Old behavior was that if connect called back with an error, the promise would get rejected but the cb function would never get called.
* Test that Pool.query passes connection errors to callback
* Fixes to standardjs compliance
* Support function-like construction
Remove the necessity of using `new` in front of the `Pool`, i.e. allow it to be used as a regular function. This is following https://github.com/brianc/node-postgres/issues/1077
* add Pool factory test
