Refactor `ClientCertificateCredential` to use `AadClient`#11719

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chlowell merged 2 commits intoAzure:masterfrom

chlowell:certificate-aadclient

Jun 4, 2020

Commits on May 29, 2020

AadClient supports authentication by cert
chlowell
committed

Commits on May 30, 2020

CertificateCredential uses AadClient
chlowell
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