[Issue #195] Scoping log4j libraries to test

[lizhanhui]

…j2 related libraries as test

[RongtongJin]

@lizhanhui Although DLedger is a library, it is also a program that can run independently. If all log implementation is set to test scope, this will result in no log output even for quick start. In addition, DO NOT MERGE your own PR without anyone's approval.

[lizhanhui]

Although DLedger is a library, it is also a program that can run independently.

Then you should split your library and program, and configure the runnable program with appropriate logging infra.

If all log implementation is set to test scope, this will result in no log output even for quick start.

Well engineered and designed project won't have this issue at all.

In addition, DO NOT MERGE your own PR without anyone's approval.

The issue and pull request stayed unprocessed for more than 72 hours. And it was added as a required dependency for the core project. And it now turns into a blocker issue. Make it optional or make it well engineered.