- Tweaks to the way `Client`s can be initialized (PR 143, 157)
- Removed support for the deprecated `PACHD_ADDRESS` environment variable
- Removed support for library-specific `PACH_PYTHON_AUTH_TOKEN` environment variable
- Added `Client.new_in_cluster`, which can be used to create a `Client` instance running inside a Pachyderm cluster
- Added `Client.new_from_pachd_address`, which can be used to create a `Client` instance from a pachd address/URL
- Added support for using default system certs
- Added support for client initialization with a transaction ID
- Added support for the enterprise service (PR 157)
- Added support for the auth service (PR 157)
- Added `auth_token` and `transaction_id` properties for better ergonomics (PR 157)
- Renamed `Client.metadata` to `Client._metadata`, since it should be private (PR 157)
- Some changes to `Client.transaction` to be more ergonomic and less redundant with other functionality (PR 157)