feat: Add Go Modules

[garethpaul]

Feature

Add a go.mod file to manage dependencies of a given Go project. This should allow users to specify a version when installing the GoLib vs always pulling from master.

Checklist

• [x] I acknowledge that all my contributions will be made under the project's license
• [x] I have made a material change to the repo (functionality, testing, spelling, grammar)
• [x] I have read the Contribution Guidelines and my PR follows them
• [x] I have titled the PR appropriately
• [x] I have updated my branch with the main branch
• [x] I have added tests that prove my fix is effective or that my feature works
• [x] I have added the necessary documentation about the functionality in the appropriate .md file
• [x] I have added inline documentation to the code I modified

If you have questions, please file a support ticket, or create a GitHub Issue in this repository.

[bonesyo]

+1 @garethpaul can we revive this?

[DustinHigginbotham]

Considering go modules are enabled by default in 1.16, it would be great to get this merged!

[gustavosbarreto]

Please accept this PR, it provides a better dependency management using Go modules.

[gustavosbarreto]

@garethpaul Can you please fix the tests so this can be reviewed? thanks