Release dart plugin which simply includes same version of pre-compiled framework

[rmtmckenzie]

As a long-time user of the Firestore plugin, I've had to update my Podfile numerous times to support the pre-compiled firestore ios framework. While not that much of an inconvenience, it is... somewhat annoying.

If it were possible for for a flutter plugin to be released which simply included this cocoapods dependency and nothing else, and was tied to the right versions in the pubspec, this could allow for catching this error at the pub get/upgrade level instead of when you actually go to do the build, and then having to update the Podfile. Plus it would make for a slightly easier set up - ideally it should be possible to write a flutter app without having to ever manually edit the Podfile.

There might be some complication with getting it to be tied to the right version; I haven't thought that far ahead into how it would work, but it if were possible it'd be awesome =).