Added expecta from git@github.com:github/expecta fc7ecaf3164.

This was a submodule of ReactiveCocoa -- this pulls the code so that it's
committed in this repo instead of a submodule.
Added specta from git@github.com:github/specta 4d1a78b5e.

This was a submodule of ReactiveCocoa -- this pulls the code so that it's
committed in this repo instead of a submodule.
Added xcconfigs from https://github.com/jspahrsummers/xcconfigs bbb2bee4e.

This was a submodule of ReactiveCocoa -- this pulls the code so that it's
committed in this repo instead of a submodule.
Merge branch 'master' of github.com:tipbit/ReactiveCocoa