Create data loader service

### Create data loader service

## Description:
Create a mechanism for defining and loading data-sets into postgres, suitable for use with external test-services such as NightWatch and Postman/Newman collection-runs. This should allow for developers/qa to be able to design scenarios for the automated test cases, and be easily maintained by all parties.

##Inputs
We will create a service that can connect to a PostgreSQL instance. An endpoint will allow a Tester to upload a spreadsheet representing the data for a company. The PostgreSQL data for that company will be replaced with the data from the spreadsheet.

##Outputs
The service will return a JSON file representing the data that was written to the DB. That way scripts can use the data to write assertions or whatever without needing to refer to the spreadsheet.

##Impacts
Write this as a separate service so that it doesn't impact existing services. Some impact to shared files like makefile and Docker file

##Users
QA, developers

Acceptance / DoD:
- [ ] Product Owner advised if task >= 1 full-day, or forms part of the business day
- [ ] Requires deployments
- [ ] Test coverage acceptable
- [ ] Peer Reviewed
- [ ] Production burn in completed