Revert "Add support for timeouts on RPC calls."

This reverts commit 099f7df6ca9c21e5010fd2d5e62fde3b6ea4cdf0.

Doing timeouts doesn't actually need to happen here.  It's better for
just the caller to do the timeout.
Add a timeout for the authentication requests.
Merge pull request #9 from nubs/master

Remove complicated timeout interface and just use bluebird