Confusing error/warning messages if version_requirement has extra characters

[llowder]

With version 2.2.0, when listing module deps if you put in version_requirements by mistake, you get a warning about "open ended version requirements" even if the listed version is not open ended.

This should instead flag the typo in the field name as an error since it should be version_requirement (no trailing s) instead.

Note that this only shows up if --strict-dependencies is used, but the type should probably be flagged regardless.