Add SSL certs so that we can build under nix-shell --pure

Dependencies

• [2] RFYEVKZQ Add nix-shell based build environment.

Change contents

• edit in shell.nix at line 17
  [2.99083]

  [2.99083]
  + pkgs.cacert
• edit in shell.nix at line 33
  [2.99208]

  [2.99208]
  + SSL_CERT_FILE = "${pkgs.cacert}/etc/ssl/certs/ca-bundle.crt";