Application crashes if 'period' or'data_retention' are not explicitly defined by the YAML file

[Drolla]

This issue relates to pull request #7. In case period or data_retention is not explicitly defined by the YAML configuration file, the application returns with the following failure

Read configuration file /opt/waveplus_bridge/waveplus_bridge.fusion18.basic.yaml
2021-11-14 08:45:50 - Opening CSV data log file None
2021-11-14 08:45:50 -   Error accessing CSV file! None : unsupported operand type(s) for /: 'str' and 'int'

This error is also encountered if the two parameters are not defined by the YAML file, but if they are explicitly defined by the command line arguments --period and --data_retention.

[Drolla]

Fixed with commit 5162536