Extra Text Preprocessing steps

[amrayach]

what we have until now:
preprocessing_setps = {
'remove_hashtags': remove_hashtags,
'remove_urls': remove_urls,
'remove_user_mentions': remove_user_mentions,
'lower': lower,
'double_new_line': remove_double_new_line,
'wordnet_augment_text': augment_text_wordnet,
}