Include some tools for the testing and remove util classes

[feed3r]

We shoud try to avoid using utility classes and static methods,

https://www.vojtechruzicka.com/avoid-utility-classes/#:~:text=Another%20problem%20is%20that%20existing,related%20to%20the%20original%20methods.

we should use some helpful packages, such as

• https://github.com/stretchr/testify: useful for assertion and mocking (my preferred for unit testing in particular)
• https://github.com/onsi/ginkgo: This seems useful for the Integrations / e2e tests
• https://onsi.github.io/gomega: This seems related with GinkGo as the preferred assertion package, seems an overkill to me, but let's consider it