* 🐛 keep the empty dictionary though it looks useless but charts needs them. fix#555
* 👕 keep empty array too. update 📖
* 🎨 minor tweaks on the source code
* Update: pink test folder
* Update: changelog update
* 🐛 fix theme color problem for themes other than dark, #544
* 🔬 test remove_key_with_none_value and whitening
* 📚 update docs and pump version
* Update json_serializable.py
* Update __init__.py
* 💚 fix unit test failures
* 🔥 get rid of dev code
* 💚 pass all unit tests
* 👕 use python 2 to generate the fixtures
* 🔥 remove empty dictionary that resulted from cleaning
* 🔬 more test cases. 👕 whitening
* 💚 ignore basestring please, flake8
* 🔨 code refactor test
* 🔨 address review feedbacks
* 💄 change single quote
* Update: docs update
* Update: img link update
* Update: docs update
* Move coordinate data to local data files.
* Rename coordinates data file
* Refactor code
* Fix
* Format code
* Refactor as utils package
* Fix Empty value for lazy
* ✨ initial prototype to pass on python functions into echarts options
* ✨ enable more function based label formatters and 💚 make unit test pass
* 💚 make travis happy
* 💚 install pyecharts-javascripthon on appveyor
* 🔬 test javascript functions
* 🎨 tuning ci system
* 📚 update documentation
* 📚 update xaxis_formatter and 💚 make python 27 pass
* 👕 make flake8 happy
* 💚 appveyor, do conditional install plz
* 💚 appveyor, do conditional install plz
* 💚 skipping pyecharts-javascripthon on appveyor
* 🎨 make different test configurations so that they pass and test the individual aspects
* 🔥 remove unless test code
* 🐛 fix the bug to make pyecharts-javascripthon on python 3.5. 3.6 optional
* 🔨 code refactoring
* 🔨 relocate the python356 exception to add_a_new_function
* 🔨 relocate json_dumps
* ✨ support custom polar. #461
* 📚 document render_item
* 🔨 code refactoring on custom polar chart
* 🔥 remove percentage formatter
