swagger-parser-v2-converter converts default value for array incorrectly

For a schema of type array, the default value must be an array (obviously), not a string.

For input that has a default value of type array (correct), the swagger-parser-v2-converter produces an OpenAPI v3 file that has a default value of type string (wrong).

How to reproduce:

1. Store this file as v2.yaml.

v2.yaml.gz

2. Store this file as ConvertOpenAPIV2ToV3.java.

ConvertOpenAPIV2ToV3.java.gz

Compile it with a classpath that contains
slf4j-api-1.5.8.jar
slf4j-jdk14-1.5.8.jar
jackson-core-2.9.9.jar
jackson-dataformat-yaml-2.9.9.jar
jackson-databind-2.9.9.jar
jackson-annotations-2.9.9.jar
commons-io-1.4.jar
commons-lang3-3.1.jar
swagger-models-2.0.8.jar
swagger-parser-v3-2.0.12.jar
swagger-core-2.0.8.jar
swagger-parser-core-2.0.12.jar
swagger-parser-v2-converter-2.0.12.jar
swagger-parser-1.0.44.jar
swagger-core-1.5.22.jar
swagger-models-1.5.22.jar
snakeyaml.jar

3. Run it with two arguments, namely the absolute file name from step 1 and the absolute file name of the destination file.

4. The output I got is:

v3.yaml.gz

As you can see, it has

default: '["registration"]'

Instead it should have

default: ["registration"]

or, equivalently,

default:
  - registration

Start by running the supplied v2.yaml through ConvertOpenAPIV2ToV3.java and inspect the swagger-parser-v2-converter handling of schema default values. Confirm the generated v3.yaml preserves an array default as an array rather than serializing it as a string.