Automate company sponsorships

Currently, company sponsorships are done manually so we can request logos that work on our dark background. However, we don't get notified when a company cancels their sponsorship so we have to check back monthly and remove anyone that stops sponsoring.

It would be great to automate this process. Maybe the easiest step is to notify us when someone stops sponsoring.

该 issue 没有指明文件、测试、赞助服务提供商或通知目标。首先确定公司赞助目前是如何记录在 gulp 网站上的，以及哪些服务可以报告取消；完成标准应包括一个已定义的自动取消通知工作流和移除流程。

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