Feat/reverse many to many

[loganripplinger]

Overview

This adds the ability to reverse query a relationship.

Previously you were only able to query /credentials/programs but this allows you to also query /programs/credentials.

Checklist

• PR has a descriptive enough title to be useful in changelogs

Notes

In this solution I use _asdict() which may be problematic down the road. Relevant stackoverflow -- https://stackoverflow.com/questions/1958219/convert-sqlalchemy-row-object-to-python-dict

Testing Instructions

• Start after checking out this branch.
• To be safe ensure you have killed any running docker images related to Data Resource API.
• Create the data resource and run it with;

docker build -t brighthive/data-resource-api:1.0.0-alpha .
docker-compose up

• Allow the data resource to initialize for a minute or two. You may see errors occur at first.
• Open POSTMAN.
• Create two credentials by performing a POST to http://localhost:8000/credentials with the following JSON body:

{
	"credential_name": "credential test"
}

• Create a program with two credentials by performing a POST to http://localhost:8000/programs with the following JSON body:

{
	"program_name": "aprogram 1",
	"program_code": 1,
	"program_description": ".",
	"program_status": ".",
	"program_fees": 1,
	"eligibility_criteria": ".",
	"program_url": ".",
	"credentials": [1,2]
}

• Get the data by performing GET http://localhost:8000/credentials/1/programs

• You should see

{
    "programs": [
        1
    ]
}

handles #6