generator-api The value (generator's option) must be either boolean or string. Default to `false`

[pfwd]

When running yarn run generate-api the following errors are reported

[main] WARN  o.o.codegen.DefaultCodegen - The value (generator's option) must be either boolean or string. Default to `false`.
[main] WARN  o.o.codegen.DefaultCodegen - The value (generator's option) must be either boolean or string. Default to `false`.

Work should be done as part of #129