[AETHER-523] Enable tagging of tost-onos project

Moreover, env vars are left blank in order to leverage
the `default` versions of each component

Change-Id: I2e53a0a883f400a3a06fb9d199521fb9da578f5b
diff --git a/jjb/repos/tost-onos.yaml b/jjb/repos/tost-onos.yaml
index 13e40ca..b581054 100644
--- a/jjb/repos/tost-onos.yaml
+++ b/jjb/repos/tost-onos.yaml
@@ -20,8 +20,6 @@
       - 'tag-check':
           dependency-jobs: 'license-check_tost-onos'
       - 'private-make-test':
-          make-test-vars: |-
-            ONOS_BRANCH=onos-2.2
           make-test-targets: 'docker-build'
           junit-allow-empty-results: true
           build-node: '{bigger-build-node}'
@@ -29,11 +27,10 @@
 - job-group:
     name: 'publish-tost-onos-jobs'
     jobs:
+      - 'version-tag'
       - 'private-docker-publish':
           docker-repo: 'tost'
           docker-registry: 'registry.aetherproject.org'
           maintainers: 'charles@opennetworking.org, pier@opennetworking.org'
           build-timeout: 30
-          extraEnvironmentVars: >-
-            ONOS_BRANCH=onos-2.2
           dependency-jobs: 'version-tag'