Don't create pipes for `P.spawn` by default.

Pipes will block if they get enough input, and our users are not listening
to the pipe (we're not even exposing it to the caller).

Change-Id: Iff417f74db2724ef27f64d3cc5d1c9bc40d77bf4
Update dependencies.

* `commander` to 2.5.0
* `es6-shim` to 0.20.2
* `prfun` to 1.0.1
* `jshint` to 2.5.0
* `request` to 2.47.0
* `mocha` to 2.0.1

The `retry-request` module required slight updates for `request` 2.47.0.

Change-Id: Iedbcfcc77519aa8fdc5c24c72013eec6f793bcf4
Merge "Don't create pipes for `P.spawn` by default."
Merge "Update dependencies."