lack of structure validity

[ik5]

When creating the yaml file, there is no check to see if something that is required is missing, but it just try to execute the parameter with null value.

For example misspelling of field:
max_concurret:

Will not trigger that the max_concurrent: field is missing, but will add the -l field without integer or other type of value.

[bklang]

Related to this: we should catch steps that don't exist and throw an error. Right now they are silently ignored.