Consider using Pact for API testing and perform more contract tests

## Overview
Pact is a tool that makes it fast, easy and reliable to test your APIs and microservices during development. It implements a style of testing referred to as consumer-driven contract testing. It's ideally suited to environments [where](https://docs.pact.io/) there are a number of teams building out a large distributed system. You can read more about that here, but as a brief introduction:

Contract testing is a technique for testing an integration point by checking each application in isolation to ensure the messages it sends or receives conform to a shared understanding that is documented in a "contract".

## Ref

- https://pactflow.io/go/
- https://github.com/pact-foundation/pact-go