Change logging scheme for validation

[sgsmob]

Description

Update the logging scheme for validation to properly log indicator and validation output.

Changelog

• Indicator runner actually logs its results
• ValidationReport.log() now takes an additional parameter specifying the logger to use

[krivard]

You have a linter error:

. env/bin/activate; pylint delphi_utils
************* Module delphi_utils.validator.report
delphi_utils/validator/report.py:10:68: W0613: Unused argument 'log_filename' (unused-argument)

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Your code has been rated at 9.99/10

[sgsmob]

You have a linter error:

. env/bin/activate; pylint delphi_utils
************* Module delphi_utils.validator.report
delphi_utils/validator/report.py:10:68: W0613: Unused argument 'log_filename' (unused-argument)

-----------------------------------
Your code has been rated at 9.99/10

Done