fix(registry): use docker cache
fix(builder): validate that properly formed slugs are added correctly
Retry downloading deisctl
feat(controller): bump API to v1
fix typo
ref(database): reduce image size
Merge pull request #2205 from ngpestelos/patch-1

fix typo
Merge pull request #2186 from bacongobbler/controllerv1

feat(controller): bump controller API to v1
Merge pull request #2188 from mboersma/catch-docker-add-zero

fix(builder): validate that properly formed slugs are added correctly
Merge pull request #2206 from aledbf/reduce_database_size

ref(database): reduce image size
Merge pull request #2173 from aledbf/registry_use_docker_cache

fix(registry): use docker cache
Merge pull request #2195 from glomium/master

Retry downloading deisctl
ref(user-data): "make discovery-url" copies from user-data.example

This also adds contrib/coreos/user-data to .gitignore, so that local
changes to this essential file do not cause "git status" to mark the
repo as dirty.