Simplify the Usage of Lexicon in Chinese NER

Benchmark Model Rank Results
chinese-named-entity-recognition-on-msraLSTM + Lexicon augment#16F1: 93.5
chinese-named-entity-recognition-on-ontonotesLSTM + Lexicon augment#12F1: 75.54
chinese-named-entity-recognition-on-resumeLSTM + Lexicon augment#8F1: 95.59
chinese-named-entity-recognition-on-weibo-nerLSTM + Lexicon augment#13F1: 61.24