added loggers

pytorch_lightning/logging/__init__.py

@@ -77,7 +77,7 @@ from os import environ
 from .base import LightningLoggerBase, rank_zero_only
 from .tensorboard import TensorBoardLogger
 
-all = ['TensorBoardLogger']
+all = []
 
 try:
     # needed to prevent ImportError and duplicated logs.
@@ -100,6 +100,8 @@ try:
 except ImportError:
     pass
 
+all.append('TensorBoardLogger')
+
 try:
     from .test_tube import TestTubeLogger
     all.append('TestTubeLogger')