v1.3.0 Release

Feature & Improvement:

• Support failing workflow with results
• Improve workflow uncompleted error return(canceled, failed, timeout, terminated)

Note that the new behaviors require 1.3+ version of iWF server to support.

What's Changed

• Improve and add more handling workflow uncompleted by @longquanzheng in #40

Full Changelog: v1.2.1...v1.3.0