Support for torch-lightning in NER examples (#2890)

* initial pytorch lightning commit

* tested multigpu

* Fix learning rate schedule

* black formatting

* fix flake8

* isort

* isort

* .

Co-authored-by: Check your git settings! <chris@chris-laptop>

examples/ner/run_pl.sh

@@ -0,0 +1,21 @@
+# Require pytorch-lightning=0.6
+export MAX_LENGTH=128
+export BERT_MODEL=bert-base-multilingual-cased
+export OUTPUT_DIR=germeval-model
+export BATCH_SIZE=32
+export NUM_EPOCHS=3
+export SAVE_STEPS=750
+export SEED=1
+
+python3 run_pl_ner.py --data_dir ./ \
+--model_type bert \
+--labels ./labels.txt \
+--model_name_or_path $BERT_MODEL \
+--output_dir $OUTPUT_DIR \
+--max_seq_length  $MAX_LENGTH \
+--num_train_epochs $NUM_EPOCHS \
+--train_batch_size 32 \
+--save_steps $SAVE_STEPS \
+--seed $SEED \
+--do_train \
+--do_predict