docs(deisctl): reword comment
docs(contrib): refer to digitalocean guide
docs(installing_deis): import baremetal docs
docs(testing): add better instructions for contributors
ref(docs): error on warnings for all Makefile targets
docs(*): add Troubleshooting Deis docs
chore(release): update version to v0.15.1
chore(release): update version in master to v0.15.1+git
fix(tests): Allow TLS

Fixes https://github.com/deis/deis/issues/2230
docs(managing_deis): add MDS removal instructions
docs(*): specify required CoreOS version
fix(build.sh): fail on errors in Dockerfile two-tier builds

Without "set -e" at the top of each build.sh script, errors would
not propagate to the parent "docker build" process. In the case
of controller, this was masking a missing dependency which is now
fixed.
fix(registry): prefix "apt-get install" with "apt-get update"
docs(installing_deis): import gce provisioning docs
ref(installing_deis): remove unused link
fix(deisctl/units): mount deis-store only if it isn't mounted
docs(hacking): note that Docker 1.3.1 may need --insecure-registry
style(logger): add code doc strings
style(deisctl): add code doc strings
ref(deisctl): remove unused utility code

Also capitalize NewUUID() as recommended by `golint`.