ENH: Enable string input for NewickTreeReader.

Adding support to accept a string as the input.
Corresponding test is updated.

Change-Id: Ib28103bdb96989bca4c176b75e09acdf7779cd39
fix unused parameter warning

Change-Id: I387a707a2e219e68600ddd1f6d7d6c01ddd86021
Merge topic 'EnableStringInputForNewickTreeReader' into master

2b8e6857 ENH: Enable string input for NewickTreeReader.
Merge topic 'fix_warning_in_restored_test' into master

a0938d94 fix unused parameter warning