Remove exported env vars from build.sh

* Reformats make test call.
Change DB_HOST to database_hostname in Makefile

Fixes bug 1043526
Fix rabbitmq variable typo
Add default environment variables to build.sh
Rename DB_HOST to database_hostname
Remove DB_HOST setting from webapp-django
Remove PATH setting from webapp-django tests
Remove DB_USER from webapp-django jenkins tests
Replace ES_HOST envvar with elasticsearch_urls
Replace DB_USER envvar with database_username
Replace DB_PASSWORD envvar database_password.
Replace RABBITMQ_HOST envvar with rmq_host.
Replace RABBITMQ_USERNAME envvar with rmq_user
Replace RABBITMQ_PASSWORD with rmq_password.
Replace RABBITMQ_VHOST envvar with rmq_virtual_host
Fix typo on database_username in rabbitmq tests
Merge pull request #2247 from bramwelt/fix-bug-1043526-duplicate-envvars-2

Replace Jenkins Environment Vars