Add link to Jenkins server in Collaborator Guide.
PR-URL: https://github.com/nodejs/io.js/pull/1995
Reviewed-By: Chris Dickinson <christopher.s.dickinson@gmail.com>
Reviewed-By: Jeremiah Senkpiel <fishrock123@rocketmail.com>
All bugfixes require a test case which demonstrates the defect. The
test should *fail* before the change, and *pass* after the change.
+All pull requests that modify executable code should be subjected to
+continuous integration tests on the
+[project CI server](https://jenkins-iojs.nodesource.com/).
+
### Involving the TC
Collaborators may opt to elevate pull requests or issues to the TC for