Octobot-backtesting

Updated
**Requirements**
- Commons version to 1.3.0
- CCXT version to 1.23.67

Fixed
- Remove hard octobot_evaluators import

Added
- Backtesting finished event

Updated
- Data converters
- Backtesting API
- DataFile converter API
- Database error handling
- IndependentBacktesting flexibily for strategy optimizer

Fixed
- Compiled double accuracy

Added
- Independent backtesting handling

Updated
- Backtesting API
- Importer API
- DataFile API

Updated
- Backtesting API
- Importer API

Updated
- Backtesting API
- Backtesting workflow