Add optional path to job definitions for JJB

Add optional variable `job_builder.config.path` to specify subdirectory
in project containing job definitions.

Change-Id: Icbf51fa5d2ad1b0e98c7417ce669c86102d0fed7
diff --git a/jenkins/job_builder.sls b/jenkins/job_builder.sls
index 15ada34..01c5238 100644
--- a/jenkins/job_builder.sls
+++ b/jenkins/job_builder.sls
@@ -62,7 +62,7 @@
 
 jenkins_job_builder_jobs_update:
   cmd.run:
-  - name: jenkins-jobs update /srv/jenkins/job_builder_config
+  - name: jenkins-jobs update /srv/jenkins/job_builder_config/{{ job_builder.config.path }}
   - require:
     - git: {{ job_builder.config.address }}
     - file: {{ job_builder.dir.conf }}/jenkins_jobs.ini