CSR signing

aws acm-pca issue-certificate \
      --certificate-authority-arn arn:aws:acm-pca:us-east-1:521840836442:\
      certificate-authority/2280fe40-b791-4a53-b49e-27613564ca3b \
      --csr cert.csr \
      --signing-algorithm "SHA256WITHRSA" \
      --validity Value=365,Type="DAYS" \
      --idempotency-token 1234