Adds --config_file=.... flag to specify the location of the config.yaml file
Adds the ability to specify SALT_CONFIG_FILE in the environment.
When specified this provides the location of the configuration file, but passing the --config_file=... options takes precidence over the environment variable
When not set and the flag is not passed, it looks in the old default location of config_files/config.yaml but this is relavent to the directory in which SALT was invoked.
--config_file=....flag to specify the location of theconfig.yamlfileSALT_CONFIG_FILEin the environment.--config_file=...options takes precidence over the environment variableconfig_files/config.yamlbut this is relavent to the directory in which SALT was invoked.Fixes #11