Add verbose flag to mock command

Barney builds have introduced an idle timeout; if a build step doesn't
output logs to the console for 30 minutes, it cancels the build.
In eext case, 'eext mock' is the barney build step which at time can
take a long time to complete. Previously, we were only redirecting
stdout and stderr to barney, not the entire logs. This was causing some
eext builds to get timed out, since no ouptut was seen for > 30 min.
Hence we add a '--verbose' flag to the mock step of eext to ensure that
builds are not cancelled due to idle timeout.

impl/mock.go

@@ -182,6 +182,8 @@ func (bldr *mockBuilder) mockArgs(extraArgs []string) []string {
 	}
 	if util.GlobalVar.Quiet {
 		baseArgs = append(baseArgs, "--quiet")
+	} else {
+		baseArgs = append(baseArgs, "--verbose")
 	}
 
 	mockArgs := append(baseArgs, extraArgs...)