Models: Add support for ES6 class fields (through a babel plugin)

[Duckers]

The default es2015 implementation does not support class fields, but most transpiler environments are configured to support it anyway. So instead of

class Foo {
     constructor() { this.bar = 1 }
}

we can simply write

class Foo {
    bar = 1
}

I've done some googling but not been able to determine what is the most kosher plugin to use.

[sebbert]

This feature is still in proposal stage 3, and not yet part of any ECMAScript standard. Therefore, I'm reluctant to include it - as we can introduce this later on without breaking user code, but not the other way around.

most transpiler environments are configured to support it anyway

Do you have any data to support this claim?