Update Bolts to work on OS X 10.10 and enable modules. Update iOS to include armv7s.

Changes:
- Converted Bolts for OS X to `framework` product-type. OS X had it since a long time ago, so it shouldn't affect anyone.
- Added Info.plist for OS X version of Bolts. This is required on 10.10 right now.
- Added `armv7s` to ARCHS for iOS, so everyone can still use it.
- Enabled module support in OS X bolts. (`@import Bolts;` now works).
- Cleaned up build scripts for new OS X deployment via `framework`.
- Cleaned up .travis.yml file

Test #1:
- `./build_framework.sh` inside `scripts` folder.
- Try using the version that is built on Xcode 5 / 6 in few applications for both iOS and OSX.

Test #2:
- `./build_framework.sh` inside `scripts` folder.
- Try using Bolts for OS X with Xcode 6.1 Beta targeting OS X 10.10
- Codesign shouldn't fail now.

Test #3:
- Try using Bolts for OS X in an example project
- Replace `#import <Bolts/*>` with `@import Bolts;`
- It shouldn't fail.

Oh yeah and the last one - travis CI now passes.