"go" missing from client codegen languages

Description

The CLI version of codgen (3.0.19) is missing the option to create go client SDKs. I only see the go-server version present.

➜ 6.0r swagger-codegen version
14:23:58.422 [main] DEBUG io.swagger.codegen.v3.cli.SwaggerCodegen - there are not options for command 'langs'
14:23:58.424 [main] DEBUG io.swagger.codegen.v3.cli.SwaggerCodegen - there are not options for command 'version'
3.0.19
➜ 6.0r swagger-codegen langs
14:24:08.938 [main] DEBUG io.swagger.codegen.v3.cli.SwaggerCodegen - there are not options for command 'langs'
14:24:08.940 [main] DEBUG io.swagger.codegen.v3.cli.SwaggerCodegen - there are not options for command 'version'
Available languages: [aspnetcore, csharp, csharp-dotnet2, go-server, dynamic-html, html, html2, java, jaxrs-cxf-client, jaxrs-cxf, inflector, jaxrs-cxf-cdi, jaxrs-spec, jaxrs-jersey, jaxrs-di, jaxrs-resteasy-eap, jaxrs-resteasy, micronaut, spring, nodejs-server, openapi, openapi-yaml, kotlin-client, kotlin-server, php, python, python-flask, r, scala, scala-akka-http-server, swift3, swift4, swift5, typescript-angular, javascript]
➜ 6.0r

Swagger-codegen version

3.0.19 (OSX installed via brew)

Swagger declaration file content or url

https://gist.github.com/anichari/effdfbfe3e06c106eff97251d753dc76

Command line used for generation

swagger-codegen generate -i response_1587085110404.json -l go

Steps to reproduce

swagger-codegen generate -i -l go

Related issues/PRs

Suggest a fix/enhancement

Start by reproducing the issue with swagger-codegen langs and swagger-codegen generate -i <specfile> -l go on version 3.0.19, using the linked Swagger declaration for input. Trace how available languages are registered and how the existing go-server generator is exposed; done means Go appears as a client option and the generation command succeeds.