ApolloCodegenLib doesn't include an equivalent option for customScalarsPrefix

[CraigSiemens]

I'm trying out the codeine using SPM and I've found that the flag --customScalarsPrefix that we've been using is not available.

We use the --passthroughCustomScalars flag to define out own types for the scalars, and --customScalarsPrefix="Scalar." to prevent name conflicts between scalars and Foundation types. For example Scalar.Date is using a custom struct for year, month, day and shouldn't conflict with Foundation.Date

[designatednerd]

Ah yeah, will get that added in

[designatednerd]

@CraigSiemens PR #1215 is up