Add to CT log list Digicert2 and Symantec Sirius.

Digicert CT2 completed probation on 2017-Jun-04.
Symantec Sirius completed probation on 2017-May-30.

R=rsleevi@chromium.org
BUG=698094,692782

Review-Url: https://codereview.chromium.org/2923193002
Cr-Original-Commit-Position: refs/heads/master@{#481160}
Review-Url: https://codereview.chromium.org/2970713002 .
Cr-Commit-Position: refs/branch-heads/3112@{#508}
Cr-Branched-From: b6460e24cf59f429d69de255538d0fc7a425ccf9-refs/heads/master@{#474897}
1 file changed