add go.mod and go.sum to support go modules function

[xserve98]

Go Modules: https://github.com/golang/go/wiki/Modules

[jtvjorge]

Is there a specific use case for go modules you are looking to satisfy? Are you looking for go module support generally?

We're interested in adding modules but unfortunately the transition will involve quite a bit more than just adding go.mod and go.sum files as import paths will need to change. It may be some time before we're able to fully support modules.

[bufdev]

Related use case in #152

[xserve98]

Thank you