Emoji

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* Extract aliases from cheat sheet and youtube
* Fix extracting translations from emojiterra
* Update EMOJI_DATA with new aliases and translations

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* Added new function purely_emoji() | Check if a string contains only emojis

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* Fix Malformed zero width joiner (\u200d) causes IndexError

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* Added support for Multi-person skintones
* Removed support for Python 2, 3.4, 3.5
* The logic from demojize() is moved to two separate private function tokenize() and filter_tokens() in a new file emoji/tokenizer.py
* A new public function analyze() is available and that supports the multi-person skintones

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* Added Japanese and Korean

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* Added Indonesian and Simplified Chinese
* Bug fixing