Merge branch 'master' into dev

🔖 Pre-Releasing / Version tags.

🔖 Pre-Releasing / Version tags.

🔖 Releasing / Version tags.

Merge pull request justauth#87 from justauth/add-code-of-conduct-1

Create CODE_OF_CONDUCT.md

Merge branch 'dev'

# Conflicts:
#	docs/references.md

Merge branch 'master' of https://gitee.com/yadong.zhang/JustAuth

🔖 发布1.15.4-alpha（1.15.3-alpha不可用）

🔖 发布 1.15.3-alpha 解决推特登录异常的BUG

🔖 临时发布 1.15.2-alpha 解决领英获取token发生异常的问题