Bumps request library version to v2.60.0, this solves an issue with HTTP proxies. HTTP_PROXY and NO_PROXY env variables should now work as expected for all requests. See issue #40

• 307 redirects from etcd 0.4.x clusters when using SSL didn't work properly because of a change in the underlying request library. See issue #39

Minor fixes for syncronous operations, better handling of server failure.

• Adds support for synchronous operations (@brockwood) - See Synchronous Operations in readme.
• Adds support for iojs.
• Drops support for nodejs 0.8 (use v3.x.x).
• Upgrade dependencies.