Allow batch runs

[aspeake]

Allow batch runs using > 1 yaml config file. This will likely depend on https://github.com/trynthink/scout/issues/365

User would run workflow pointing to directory yml files and scout would run ecm_prep and run.py on each of those config files and store in distinct results folders at ./results/<custom_config_name>/....

Features:

• One command to run n yml files python scout/run_batch.py --yaml_dir <./my_ymls> which would call ./scout/run_workflow.py alternatively bring in a "batch" capability to run_workflow.py
• Lump yml files that have common ecm_prep arguments excluding the ecm downselect fields, run as one single ecm_prep.py call. This will create a superset of ECMs in run_setup.json
• The above would require changes to run.py to reference the yml ecm or some yml-specific list of ecms
  • Maybe: new method for extracting list of ecms (regex + ecm list arg), call that in the batch script and pass to run.py or write to run_setup.json
• What happens if some ymls files hit an exception but keep running (https://github.com/trynthink/scout/issues/255) once we get to run.py? May want to have some approach to storing exceptions and the ability to skip over those that fail, something like a run_setup_batch.json that stores active/inactive ecms plus "exceptions".

First pass:

• scenario where all ymls are alike except for ECMs
• Run a single ecm_prep.py run with all ECMs
• Run run.py with just the yml-specific ecms