we should support this type of auth config under auth.github

   github-cloud:

      production:

        clientId: ${GITHUB_CLOUD_OAUTH_CLIENT_ID}

        clientSecret: ${GITHUB_CLOUD_OAUTH_CLIENT_SECRET}

    github-2:

      production:

        clientId: ${GITHUB_FORD_OAUTH_CLIENT_ID}

        clientSecret: ${GITHUB_FORD_OAUTH_CLIENT_SECRET}

        enterpriseInstanceUrl: URL

the header names can remain X-Authorization-<provider>
In this case 
X-Authorization-Github-Cloud
and 
X-Authorization-Github-2