Update config for Go SDK

[jhendrixMSFT]

Switched to package-2018-04 per request of the compute team (similar
change was done for package-2017-03).
Removed package-2017-12 for now as it fails to build.

This checklist is used to make sure that common issues in a pull request are addressed. This will expedite the process of getting your pull request merged and avoid extra work on your part to fix issues discovered during the review process.

PR information

• The title of the PR is clear and informative.
• There are a small number of commits, each of which have an informative message. This means that previously merged commits do not appear in the history of the PR. For information on cleaning up the commits in your pull request, see this page.
• Except for special cases involving multiple contributors, the PR is started from a fork of the main repository, not a branch.
• If applicable, the PR references the bug/issue that it fixes.
• Swagger files are correctly named (e.g. the api-version in the path should match the api-version in the spec).

Quality of Swagger

• I have read the contribution guidelines.
• My spec meets the review criteria:
  • The spec conforms to the Swagger 2.0 specification.
  • The spec follows the guidelines described in the Swagger checklist document.
  • Validation tools were run on swagger spec(s) and have all been fixed in this PR.

[vladbarosan]

LGTM

[AutorestCI]

Automation for azure-sdk-for-node

A PR has been created for you based on this PR content.

Once this PR will be merged, content will be added to your service PR:
Azure/azure-sdk-for-node#2558

[AutorestCI]

Automation for azure-libraries-for-java

A PR has been created for you based on this PR content.

Once this PR will be merged, content will be added to your service PR:
AutorestCI/azure-libraries-for-java#2

[AutorestCI]

Automation for azure-sdk-for-go

A PR has been created for you:
Azure/azure-sdk-for-go#1443

[jhendrixMSFT]

@AutorestCI regenerate azure-sdk-for-go

[AutorestCI]

Automation for azure-sdk-for-python

A PR has been created for you based on this PR content.

Once this PR will be merged, content will be added to your service PR:
Azure/azure-sdk-for-python#2276

[jhendrixMSFT]

@AutorestCI regenerate azure-sdk-for-go

[AutorestCI]

Encountered an unknown error

Traceback (most recent call last):
  File "/usr/local/lib/python3.6/dist-packages/swaggertosdk/github_tools.py", line 32, in exception_to_github
    yield context
  File "/usr/local/lib/python3.6/dist-packages/swaggertosdk/restapi/bot_framework.py", line 104, in manage_comment
    response = getattr(self.handler, orderstr)(webhook_data.issue, *split_text)
  File "/usr/local/lib/python3.6/dist-packages/swaggertosdk/restapi/restbot.py", line 54, in regenerate
    return self.rebuild(issue, repotag)
  File "/usr/local/lib/python3.6/dist-packages/swaggertosdk/restapi/restbot.py", line 36, in rebuild
    self.sdk_default_base
  File "/usr/local/lib/python3.6/dist-packages/swaggertosdk/restapi/github_handler.py", line 150, in rest_pr_management
    sdk_tag=sdk_tag
  File "/usr/local/lib/python3.6/dist-packages/swaggertosdk/SwaggerToSdkNewCLI.py", line 284, in generate_sdk_from_git_object
    sdk_repo.git.push('origin', branch_name, set_upstream=True)
  File "/usr/local/lib/python3.6/dist-packages/git/cmd.py", line 551, in <lambda>
    return lambda *args, **kwargs: self._call_process(name, *args, **kwargs)
  File "/usr/local/lib/python3.6/dist-packages/git/cmd.py", line 1010, in _call_process
    return self.execute(call, **exec_kwargs)
  File "/usr/local/lib/python3.6/dist-packages/git/cmd.py", line 821, in execute
    raise GitCommandError(command, status, stderr_value, stdout_value)
git.exc.GitCommandError: Cmd('git') failed due to: exit code(1)
  cmdline: git push --set-upstream origin restapi_auto_2755
  stderr: 'To https://AutorestCI:58ab395c311d1bd75b3e1db1cc8adaf9acc42afe@github.com/Azure/azure-sdk-for-go.git
 ! [rejected]        restapi_auto_2755 -> restapi_auto_2755 (fetch first)
error: failed to push some refs to 'https://AutorestCI:58ab395c311d1bd75b3e1db1cc8adaf9acc42afe@github.com/Azure/azure-sdk-for-go.git'
hint: Updates were rejected because the remote contains work that you do
hint: not have locally. This is usually caused by another repository pushing
hint: to the same ref. You may want to first integrate the remote changes
hint: (e.g., 'git pull ...') before pushing again.
hint: See the 'Note about fast-forwards' in 'git push --help' for details.'

[jhendrixMSFT]

@AutorestCI regenerate azure-sdk-for-go