Repeated directives are ignored

[prgood]

Description

The graphql-java library support repeatable directives as we can see here: graphql-java/graphql-java#1763
Example:
directive @Min(value : Int! = 0, country : String) repeatable on ARGUMENT_DEFINITION | INPUT_FIELD_DEFINITION

But "SchemaParser" is reading only the first repeated directive like in the example below we got only the first directive triggered:

type Query {
    test(
        minField: Int @Min(value : 30, country: "BR"),   @Min(value : 10, country: "UK")
    )
}

I think this line is part of the issue:

graphql-java-tools/src/main/kotlin/graphql/kickstart/tools/SchemaParser.kt

Line 304 in d0ee10a

if (!names.contains(directive.name)) {

Expected behavior

When more the one of a"repeatable" directive is applied to a field, all repeated directives should be processed.

Actual behavior

Only the first directive is been processed.

Steps to reproduce the bug

1. Define a directive as "repeatable" like the example above.
2. Apply this directive more then once to a single field.
3. All directives should run

[oryan-block]

Fix with #663

[jimartinmoreno]

I'm experiencing the same problem with version 11.1.0 and 12.0. Is this feature available in any kickstart version?