Pybsn

Added
- added optional parameter `params` to all BigDbClient and Node request methods. It allows
specifying additional query paramters for the BigDB request (e.g., `transaction` or
`state-type` parameters).
- added optional parameter `params` to RPC to manually initiate async RPC calls.
e.g., `initiate-async-id`, `async-id`
Removed
- python 2 support has been removed.
- python 3.5 support has been removed.
- python 3.6 support is deprecated, and may be removed in the future.
- nosetest has been removed as dependency.

Removed
- `pybsn.bcf`. Pybsn contained a a very partial "Porcelain" API layer called pybsn.bcf. It
has been removed since it was unused and very incomplete.

Added
- `pybsn-repl` - optional parameter `-c` allows specifying a non-interactive command to run
(like ipython).

Deprecated
- Note: this is the last pybsn version to support python 2. Please upgrade to python 3 if
you want to consume newer pybsn versions.

Added
- `pybsn-repl` - optional parameter `env-token` allows specifying
the name of an environment variable to read the session token from.

Added
- `pybsn.connect` - optional parameter `session_headers` allows specifying
request headers to be included with all requests.

Added
- Ability to log request/response bodies

Changed
- Connect API signature to remove unused variable

Fixed
- Handling of RPCs that don't return data
- Python 2 bug with unicode strings in predicates
- Issue where full schema of RPC was not displayed

Added
- Support for API tokens

Changed
- Discovery method for controller scheme and port