GitLab

**Description**
Fix bug of duration feature for model benchmarks in distributed mode.

**Major Revision**
- Add all_reduce to sync the result of is_finished(the function to judge whether the model benchmark should be stopped) in each step 
  - to avoid inconsistency between different ranks to determine duration end (some rank may enter one more step and can never finish)
- Add torch.cuda.synchronize() before and after step time measuring in train_step() for all model benchmarks
  - some operations in train_step() maybe async resulting incorrect step time records (for example, lstm) 

**Description**
Remove fp16 samples type converting time for training cnn and lstm inference.

**Description**
Remove fp16  samples type converting time for cnn and lstm models.

Add transformers for TensorRT inference.

* Benchmarks: Add Benchmark - Add LSTM model benchmarks.

Benchmarks: Code Revision - Fix some issue for BERT benchmark. (#58)

Benchmarks: Add Benchmark - Add Pytorch BERT benchmarks, including bert-base and bert-large.   (#20)

* add pytorch bert benchmarks.

* revise code

* fix issue

* revise code.
Co-authored-by: Guoshuai Zhao <guzhao@microsoft.com>