Update aktualizr dependency list in readme.
Update aktualizr dependency list in readme.

Prefer clang-format-3.8. google-mock is not necessary since it is
included as part of the repo.

advancedtelematic/sota_client_cpp,advancedtelematic/aktualizr,advancedtelematic/aktualizr,advancedtelematic/aktualizr,advancedtelematic/sota_client_cpp,advancedtelematic/aktualizr