Add support for CocoaPods and Carthage

[bendingspoons]

Add support for CocoaPods and Carthage

[alaincaltieri]

Every time a push is performed in the repo (thereby including Pull Requests) TravisCI will perform any tests available and report that information to github. This is the corner stone of any CI system and we should have it in place.

The release process gets a bit more complicated. We need to:

• Create a tag with the correct version
• Verify the build was passing for the commit hash selected
• Generate the documentation and upload it to Github pages with the proper version
• Generate Cocoapods release
• Generate Carthage release
• Write a description for the release on Github (what's new)

Each one of these tasks, if done manually, is tedious and time consuming. I'll start by producing tools for automating each one of them individually. They'll be the building bricks for any automatic procedure we may develop afterwards and are required anyway.

[alaincaltieri]

Status update: the simple travis builds are already setup (needs the repo to be public to be properly tested)

I'm working on a simple command line tool to automate the release process. Language of choice Python. First version will not be fancy but should work, and it'll cover all the points mentioned in my last comment here.

Also, I'll add the relevant shields to the readme when everything is setup