Resolve warning
Resolve warning

Deprecated features used!
  "method access to node attributes (node.foo.bar) is deprecated and will be removed in Chef 13, please use bracket syntax (node["foo"]["bar"]) at 5 locations:
    - /var/chef/cache/cookbooks/java/attributes/default.rb:22:in `from_file'
juliandunn/java,GannettDigital/chef-java,GannettDigital/chef-java,juliandunn/java,juliandunn/java,GannettDigital/chef-java