* [FEATURE] Config Validation
* check configuration for invalid keys on startup
* allow users to manually trigger all configuration validation on a file using a cmd
* setup all defaults in config template and run tests against it to prevent accidents
* use tests to check bad configuration values are caught
* use tests to check old configuration values are caught
* add tests for specific key errors
* resolve merge conflicts
* nolint prealloc for test
* [FEATURE] File Secret Loading
* add a validator for secrets
* run the secrets validator before the main config validator
* only allow a secret to be defined in one of: config, env, file env
* remove LF if found in file
* update configuration before main config validation
* fix unit tests
* implement secret testing
* refactor the secrets validator
* make check os agnostic
* update docs
* add warning when user attempts to use ENV instead of ENV file
* discourage ENV in docs
* update config template
* oxford comma
* apply suggestions from code review
* rename Validate to ValidateConfiguration
* add k8s example
* add deprecation notice in docs and warning
* style changes
* added support for listing multiple domains and multiple subjects
* updated documentation to show use of multiple domains and subjects
* updated config.template.yml to display multiple domains as a list
* updated config.template.yml to display multiple subjects as a list
* updated docs/configuration/access-control.md to display multiple domains as a list
* updated docs/configuration/access-control.md to display multiple subjects as a list
* removed redundant check that always returned true
* Commentary definition for `weak`
* [FEATURE] Support writing logs in a file.
* Add documentation about logs file path.
* Rename logs_level and logs_file_path into log_level and log_file_path.
* Update BREAKING.md
Fixes#338
Co-authored-by: Amir Zarrinkafsh <nightah@me.com>