[#54742738] Adds Hdfs.details to return details about an hdfs path.

- Returns a new object type 'HdfsEntityDetails' to be used in ruby land
- Implements the details method for all 4 plugins
- Adds hamcrest to the pom for testing
[#54742738] Parse long date values to date strings in HdfsEntityDetails

- Use SimpleDateFormat for consistency with HdfsEntity
[#54742738] Use permissions instead of permission
[#54742738] Generalize tests in order to not depend on existing files

- Smoke test for HdfsEntityDetails