message: Add a new line to the JSON output.
  This should fix
diff: @@ -79,6 +79,7 @@ public final class JsonKeysetWriter implements KeysetWriter {
  public void write(Keyset keyset) throws IOException {
  try {
  outputStream.write(toJson(keyset).toString(4).getBytes(UTF_8));
  + outputStream.write(System.lineSeparator().getBytes(UTF_8));
  } catch (JSONException e) {
  throw new IOException(e);
  } finally {
  @@ -90,6 +91,7 @@ public final class JsonKeysetWriter implements KeysetWriter {
  public void write(EncryptedKeyset keyset) throws IOException {
  try {
  outputStream.write(toJson(keyset).toString(4).getBytes(UTF_8));
  + outputStream.write(System.lineSeparator().getBytes(UTF_8));
  } catch (JSONException e) {
  throw new IOException(e);
  } finally {
  