Properly capitalize exported go types

[achew22]

Previously if the type was "myEnum" it would be written as

type myEnum string

const (
  DEMO MyEnum = "DEMO"
)

which would fail because of the capitalization difference. This fixes that.

PR checklist

• Read the contribution guidelines.
• Ran the shell script under ./bin/ to update Petstore sample so that CIs can verify the change. (For instance, only need to run ./bin/{LANG}-petstore.sh and ./bin/security/{LANG}-petstore.sh if updating the {LANG} (e.g. php, ruby, python, etc) code generator or {LANG} client's mustache templates). Windows batch files can be found in .\bin\windows\.
• Filed the PR against the correct branch: 3.0.0 branch for changes related to OpenAPI spec 3.0. Default: master.
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Description of the PR

(details of the change, additional tests that have been done, reference to the issue for tracking, etc)

[achew22]

+CC @antihax, @bvwells

[bvwells]

Hi @achew22, just wondering if there is an issue filed for this PR? Couldn't see a reference to one here, but might have missed it...

[achew22]

I didn't file one since I was just going to send a PR to fix it. Would you like me to open one? Is the description in the PR sufficient?

[antihax]

Looks ok to me. I wanted to take a stab at fixing capitalization on some of the generated variables names also but time is running away from me.

[achew22]

@antihax, does that imply you approve and it should be merged?

[bvwells]

@achew22 it might be worth adding this bug in the client test swagger located here:

https://github.com/swagger-api/swagger-codegen/blob/master/modules/swagger-codegen/src/test/resources/2_0/petstore-with-fake-endpoints-models-for-testing.yaml

So that we make sure that there isn't a regression in future.

Running https://github.com/swagger-api/swagger-codegen/blob/master/bin/go-petstore.sh will regenerate the client code.

@wing328 could you advise whether an issue needs to be logged please.

[wing328]

I'll review in the coming few days...

[achew22]

@wing328 friendly ping 😄

[wing328]

@achew22 thanks for the PR, which looks good to me (sorry for the delay in merging due to Chinese New Year celebration)

[wing328]

@achew22 I'll add "my_enum" (to cover underscore as well) to https://github.com/swagger-api/swagger-codegen/blob/master/modules/swagger-codegen/src/test/resources/2_0/petstore-with-fake-endpoints-models-for-testing.yaml later this week when I've time.

[achew22]

@wing328, thanks so much for merging! I see you've tagged it with 2.4.0 as the destination release. Is there somewhere I can track the progress of that release? This bug is blocking the next major release for grpc-gateway and my hope was to get that out today or tomorrow. Would it be possible to do a really quick 2.3.2 or something?

[wing328]

Would you consider using the -t option with the customized templates?

[achew22]

I think the idea of doing -t would be a bit unwieldy since I would have to either import the mustache templates for the entire Go client (which is a bit out of scope for my e2e test) or use the snapshot. I think what I'm going to do is prepare the patch with the snapshot and then when 2.4.0 is released enshrine that version in tests.