Property TrueTimeClient.started is needed #110
Description
Hello.
I'm starting TrueTimeClient inside my custom library. One my client is using my library and also using (and starting) TrueTimeClient. As result app crashes on precondition check with message "Already started".
I need to add option to check and NOT to start shared TrueTimeClient if it is already started to avoid the crash. Almost the same issue was here #18, but it was closed with comment, not really fixed.
As I can see, NTPClient already has "started"-property, but it is inaccessible in TrueTimeClient cause its ntp member marked as private.
It would be great to make TrueTimeClient.started available.
Thanks!