Validation of configuration file with a json schema...

Validation of configuration file with a json schema `resources/config_schema.json` using the snakemake utility **validate**. The schema includes all the fields from `tests/input_files/config.yaml`, assigns certain fields as required and forbids the use of additional fields. All of the optional fields include default values, taken from the config above, except `rule_config` which has no default.

Added author name and author email as optional fields in `tests/input_files/config.yaml`, and added it into the multiqc report.