v7.0.0

• Completely refactor existing LWRPs into Chef 12.5 Custom Resources
• Refactor zookeeper::service into a Custom Resource (#86)
• Drop apt cookbook in favor of built-in resources in Chef >= 12.11
• Migrate all logic inside resources
• Use ark to download & install ZooKeeper, rather than handling every resource directly
  • This is almost certainly a breaking change, as it moves where ZooKeeper is installed by default
  • Advantage: a symlink is created at /#{install_dir}/zookeeper, pointing to /#{install_dir}/zookeeper-#{version}, so handling paths to the current install is far easier
  • Caution: /#{install_dir}/zookeeper has been, until now, a container directory for any installations of ZooKeeper (e.g., /#{install_dir}/zookeeper/zookeeper-#{version})
• Refactor recipes to wrap resources
  • An attempt at backwards compatibility has been made, using the previous attribute-driven style
  • These attributes & recipes will be dropped in future, as per a deprecation notice added to zookeeper::default
• Add more tests in an attempt at being comprehensive of various ways this cookbook can be used