BDBag release 1.6.0

Release Notes

Minor feature release with bugfixes and dependency updates.

• Implement #37: Support external fetch transports via plug-in architecture.
• Added --output-path CLI (and corresponding API) argument for specifying output path for extracted archives.
• Added a bypass_ssl_cert_verification configuration option for the https fetch handler so that SSL certificate verification could be disabled either globally (not recommended) or on a whitelisted set of URL paths used in simple substring matches against a bag's fetch.txt URLs.
• Update the --validate-profile CLI argument so that it can take an optional keyword argument, bag-only, which can be used to bypass the otherwise automatic profile serialization validation, and therefore is suitable to use on extracted bag directories.
• Fixed issue with archive_bag API function not including empty directories when creating zip format archives.
• Modified extract_bag API function to accurately include the bag root directory path of the extracted bag archive in the return value. Previously, this value could have wound up being different from the file archive base name; for example if the archive file was renamed or was created in such a way that the base file name never matched the archived bag directory root.
• Refactored bagit-profile support. This module is no longer "vendored" internally and is now a proper external dependency intended to be pulled from PyPi. The Profile class is patched internally, as needed. This dependency is currently pinned to 1.3.1.
• Updated bdbag-profile.json and bdbag-ro-profile.json to leverage newer features of bagit-profile version 1.3. Loosened "Manifests-Required" to only require md5 for both profiles.
• Pinned bagit-python dependency version to 1.8.1.
• Added Python 3.8 and 3.9 support to setup.py metadata and travis builds.
• Dropped Python 3.4 support.