Formatting issues to be fixed for v0.2.0

[sr-gi]

There are several formatting issues that could be dealt in bulk before v0.2.0.

Keeping track of them here so we don't have to mix formatting issues in PRs.

• Whitespaces to be deleted: (https://github.com/talaia-labs/python-teos/blob/master/teos/appointments_dbm.py#L32)
• Line length over the 120 limit (https://github.com/talaia-labs/python-teos/blob/master/teos/chain_monitor.py#L89)
• Unused import (https://github.com/talaia-labs/python-teos/blob/master/teos/constants.py#L1)
• Line length over 120 (https://github.com/talaia-labs/python-teos/blob/master/teos/watcher.py#L676)
• teosd.get_config missing data_dir docs (https://github.com/talaia-labs/python-teos/blob/master/teos/teosd.py#L43)