Add fixes for voltha-protos testing

Add protoc-gen-go for Go protobuf generation
Set PATH and GOPATH in python-unit template

Change-Id: Ibe92ea06e9f5f6ff4d60455a640e3f5551cbee20
diff --git a/jjb/pypi-publish.yaml b/jjb/pypi-publish.yaml
index 0f6aca9..77cbfe6 100644
--- a/jjb/pypi-publish.yaml
+++ b/jjb/pypi-publish.yaml
@@ -5,7 +5,7 @@
     id: pypi-publish
     name: 'pypi-publish_{project}'
     description: |
-      Created by {id} job-template from ci-management/jjb/pypi-publish.yaml
+      Created by {id} job-template from ci-management/jjb/pypi-publish.yaml<br/>
       When a patch is merged, publish python modules to PyPI
 
     triggers: