Add testing with Go 1.14.0

What does this MR do?

Adds testing with Go 1.14.0 besides Go 1.13.x.

Why

This repo is a library for security products and so this MR is the first step to migrate our security products from Go 1.13 to 1.14.

What are the relevant issue numbers?

n/a

Does this MR meet the acceptance criteria?

• Tests added for this feature/bug
• Conforms to the code review guidelines
• Conforms to the Go guidelines