chore(deps): Move to go modules; Upgrade distribution to latest version.

[jfuechsl]

This PR contains the following changes:

1. Move to go modules (from glide).
2. Update to the latest deis go base image.
3. Upgrade the distribution dependency to the github.com/teamhephy/distribution fork

[Cryptophobia]

Looks real good and I would like to switch to go mods asap. Thanks @jfuechsl !

[Cryptophobia]

Can you change to use our own image here:

hephy/go-dev:v1.26.2

We are building it from here and merging upstream changes: https://github.com/teamhephy/docker-go-dev

[jfuechsl]

Pushed the change.

[Cryptophobia]

Thank you for making this fix to use our own images @jfuechsl!

[Cryptophobia]

lgtm!

[jfuechsl]

Thanks!
I see that the cli binary is checked in directly in repos that use it (https://github.com/teamhephy/slugbuilder/blob/master/rootfs/Dockerfile#L33) vs. hosting it somewhere. Will this stay that way? I'm preparing the PRs for the builders and runners.

[Cryptophobia]

Good question @jfuechsl . That is done temporary because when we were making a new release the objstorage cli all of a sudden disappeared from the old deis' google storage link and I needed a quick fix.

This is where it will reside in the future when we make a new version:
https://storage.googleapis.com/hephy-obj-storage-cli/bb8e054/objstorage

For example we can make one that is always latest tag for the cli: https://storage.googleapis.com/hephy-obj-storage-cli/latest/objstorage