Add Travis CI configuration file
Use public Git URLs to allow travis to access them
Update submodules
Move OBConnection dependency to Cocoapods

Update .gitmodules accordingly and remove references inside
GossipLeague.xcodeproj
Do not set CODE_SIGN_IDENTITY for simulator builds
Update travis configuration to build against simulator SDK

Apparently we can't build iphoneos targets due to code sign errors
Update README.md to show Travis CI build status
Remove AFnetworking from Podfile, because its already included as a OBConnection dependency