Vendoring external deps using glide

[tamccall]

No description provided.

[codeactual]

If glide doesn't support vendor pruning [1, 2], it still might be worthwhile to do it via find in the Makefile (example) after each fetch.

This commit, and any future one to upgrade deps, will contain all sorts of files that aren't licenses or built (e.g. txt, javascript, etc.).

[tamccall]

@codeactual added a glide up target in the Makefile based off of the example you gave that will perform glide up and remove unnecessary files

[tamccall]

Ran into this guy the other day would likely resolve @codeactual issues with unnecessary code in the vendor directory

[evanphx]

This is an oldie. I probably should vendor them but I'd do so with dep now instead.