fixes undefined constant error when config file is missing
…ault for 'knife node show node name -F'
- EncryptedDataBagItem.load_secret now has some basic spec tests that stub out the actual file/url reading. - s[-1] == "\n" is not what you think, but .strip does what we want here without needing a look before you leap test. - Refactored to use a "functional" case to clarify variable assignment.
--secret_file => --secret-file