TradeBook improvements

• TradeBook class improved
• order_fill_price function added to utils

Option package

Option package added

Refactoring update

• setup.py updated
• linting done
• code refactoring

Updated utils, tradebook and Meta class

This version include

• more helper functions in the utils library
• better tradebook implementation
• a simple loop Meta class for event based trading

Initial public release

This is an initial public release used in a minor production system.
Python wheel file and source distribution is also added