DCOS Enterprise Mesos Support

[kstedman9]

Added scheduler for supporting DCOS Enterprise Edition of Mesos in strict mode. Adds support for a service account to be used.

Fixed the client code to use the proper response struct from /token endpoint.

Added debug for tracing what is happening when things are not working correctly.

Also beware. I changed the library imports for gatekeeper so that I could build from local source not build from specific repo source.

[nemosupremo]

I changed the library imports for gatekeeper so that I could build from local source not build from specific repo source.

Are you using go 1.11 modules? This change is really unorthodox (projects such as gohugoio/hugo and hashicorp/vault don't do this) and I think it breaks the toolchain on <go1.10 which depends on finding packages via $GOPATH. I think the addition to support DCOS EE is a great addition, but I can't merge this with the import path potentially being broken.

[kstedman9]

I will fix the paths that is fine. I did it because the docker build kept pulling the code from github instead of my local changes. It made very hard to debug. I will work on that today and see if I can get it to work. I have seen others do it like you said but for some reason it was not working with your project.

[kstedman9]

Import Paths are fixed and checked in. Sorry about that.

[nemosupremo]

Are you using the dockerfile in this repo? There may be something wrong with it then, it shouldn't be trying to pull the code from github. I'll look into it.