Add ECA bot to https://github.com/eclipse-platform/eclipse.platform.releng.aggregator

As visible at https://github.com/eclipse-platform/eclipse.platform.releng.aggregator/pull/11 ECA check was not performed.

added ECA label

ECA check was performed. You can see it, when you click on the little green check mark next to the commit.

assigned to @fgurr

closed