Inconsistent `type` attribute in `CommandInputParameter`

[camilovelezr]

The argument called "type" of class CommandInputParameter in cwl_utils/parser/cwl_v1_*.py:

• In versions <0.31:
  CommandInputParameter.type_
• In version == 0.31:
  CommandInputParameter.type
• In version == 0.32:
  CommandInputParameter.type_

Could we agree on which one of [type, type_] will be used?

Thank you.