Automate cocoa-pod IOS release

[atalman]

Based on the following document we want to make sure we can produce complete release build: https://fb.quip.com/KhfOA9XWQkkQ

And IOS nightly builds.

We should automate the IOS release to produce binaries and test them.

This way we can be sure the binaries are build correctly.

[janeyx99]

Hopefully do by 1.12

[malfet]

@atalman referenced document is not available to the general public, so please copy relevant parts of what you expect one needs to accomplished to close this task