use marshmallow to load json

src/app.py

@@ -8,6 +8,7 @@ from sentry_sdk.integrations.flask import FlaskIntegration
 import rabbitmqqueue
 from config import *
 from db import db
+from marshm import ma
 from resources import SampleResource, SampleParameterResource
 
 """
@@ -33,6 +34,7 @@ app = Flask(__name__)
 app.config['SQLALCHEMY_DATABASE_URI'] = f"postgresql://{POSTGRES_USERNAME}:{POSTGRES_PASSWORD}@{POSTGRES_HOSTNAME}:5432/{POSTGRES_DB}"
 api = Api(app)
 db.init_app(app)
+ma.init_app(app)
 
 with app.app_context():
     db.create_all()