added comments for refactoring eval_text_model

loss function bug fix

loss function bug fix

more bug fixes

Fixed bugs in text_field_embedder and training script

Update README.md

Update README.md

deleted old files

batchified ann.build(), fixed file structure, added training script

added evaluation metrics for validation

=removed ModelOptions, hard-coded hyperparameters

Finished and tested triplet generator

modified build_corpus to read multiple files

Added corpus, neighbors, citeomaticreader. citeomaticreader has not been tested yet (we need more memory)

more bug fixes, added training tests for paper embedder and nnrank