GitLab

* add memory trainer hook

* fix bug

* add memory trainer hook

* fix import bug

* fix import bug

* add trainer hook

* fix #370 git log bug

* modify `to_tensorboard` function to support better output

* remove useless output

* change the name of `MemProfiler`

* complete memory profiler

* replace error with warning

* finish trainer hook

* modify interface of MemProfiler

* modify `__init__.py` in profiler

* remove unnecessary pass statement

* add usage to doc string

* add usage to trainer hook

* new location to store temp data file