InstallAll: add logs before and after installation

We have some issues internally about authority list installation. We
found these logs could help debug in the future.

Signed-off-by: Nan Zhou <nanzhoumails@gmail.com>
Change-Id: I99cb0c1bcd73d65207fb72c597e32a0ec4f8cd92
diff --git a/certs_manager.cpp b/certs_manager.cpp
index d8e99b7..77f279c 100644
--- a/certs_manager.cpp
+++ b/certs_manager.cpp
@@ -308,6 +308,8 @@
         elog<NotAllowed>(NotAllowedReason("Certificates limit reached"));
     }
 
+    log<level::INFO>("Starts authority list install");
+
     fs::path authorityStore(certInstallPath);
     fs::path authoritiesListFile =
         authorityStore / defaultAuthoritiesListFileName;
@@ -360,6 +362,7 @@
         objects.emplace_back(certificate->getObjectPath());
     }
 
+    log<level::INFO>("Finishes authority list install; reload units starts");
     reloadOrReset(unitToRestart);
     return objects;
 }