Version 0.1.0

Release Notes

• Add array_union function and unit test
• Add is_null function and unit test
• Add some string functions, such as pinyin, md5, sha265 and so on.
• Add some date functions, such as zodiac, zodiac_cn, dayofweek etc.
• Add some china id card functions. such as id_card_info, is_valid_id_card etc.
• Add some geo functions. such as wgs_distance etc.