Inventory-next Datapusher configuration updated

[jbrown-xentity]

User Story

As a data.gov developer, I want inventory-next to deploy datapusher using the latest configuration so that upstream repositories and best practices are being used as much as possible.

Acceptance Criteria

• GIVEN I ssh onto inventory-next
  WHEN I view the supervisorctl status output
  THEN datapusher is running

Background

Related to #1678. Blocks #1675

Security Considerations (required)

None

Sketch

• Will need to possibly create separate role to deploy using gunicorn and add tests.
• Should be able to implement upstream version; if not straightforward then create separate ticket and implement GSA current version
• Only implement this latest version for inventory-next, may need an inventory-next variable set up to implement.

[jbrown-xentity]

This PR looks to be working, but has not been fully tested and requires testing on staging. Should test classic configuration on staging (only accessible currently working version) before pushing to production.

I no longer think this is related to/blocking #2038, should be able to move forward with that ticket without merging this.