typescript: TypeError: c.getName is not a function

[cfortuner]

TypeError: c.getName is not a function

https://github.com/MozillaReality/ecsy/blob/7795dc02cef72b4b8af80275b06a8ff8e84547da/src/System.js#L61

Typescript is complaining that this function does not exist

https://github.com/MozillaReality/ecsy/blob/dev/src/Component.d.ts

But it does.
https://github.com/MozillaReality/ecsy/blob/7795dc02cef72b4b8af80275b06a8ff8e84547da/src/Component.js#L72

I'm not sure if this is my own typescript settings or if this type needs to be added, but the message is a bit vague.

Let me know and I can open a pr!