Fix references to examples in api documentation

The documentation displayed references to examples in the main docs but not in
the corresponding api reference docs.  The build had these warnings..

: WARNING: Include file u'/Users/khaido/workspace/jenkins-job-builder/doc/source/api/
../../tests/properties/fixtures/batch-task.yaml' not found or reading it failed

As pointed out by Darragh[1] the problem was that literalinclude needs a leading '/' to
correctly reference both docs.

[1] https://review.openstack.org/#/c/48783/15/jenkins_jobs/local_yaml.py

Change-Id: Ib1f8ccca40af1ee54c2bd00b2b42ba39e3c0c8e5
Add support for Test Stability with Junit

Adds test-stability option to junit test result
publisher, requires Test stability plugin to be installed.

https://wiki.jenkins-ci.org/display/JENKINS/Test+stability+plugin

Change-Id: Idd7ef1bdeaf9e6fd8881bab5729950dc717ce9f3
project_maven: allow to set private repository

The values map to these GUI choices

 * default            -> Default
 * local-to-executor  -> Local to the executor
 * local-to-workspace -> Local to the workspace

This is on the project level what the similar option is on the builder
level.

Change-Id: I90ee3385ee12a46b5ab1eb26e3af1bdbfc36946a
Merge "Add support for Test Stability with Junit"
Merge "Fix references to examples in api documentation"
Merge "project_maven: allow to set private repository"
make scm test as the example

scm module had a few existing tests so now those tests are the examples.

Change-Id: Iaf039a5bb6f3910b09198e4a800a94f3f58804f9