* Runs the Swift 3 migrator in ChattoApp.
Affects ChattoApp, ChattoAppTests, Chatto and ChattoAdditions. Does not migrate ChattoTests or ChattoAdditionsTests
* Configures Chatto And ChattoAdditions projects to use Swift 3
* Updates .travis.yml to use Xcode 8 and iPhone 7
* Uses flatMap instead of filter and force cast
* Fixes createCollectionViewLayout not being a function
* Removes useless init overrides
* Fix for new implicit unwrapping optional non-propagation rule
* Removes useless casting
* Audits accessor levels in Observable
* Fixes UIControlState.Normal replaced by UIControlState()
* Favours private over fileprivate where possible
* Audits open/public access level
* Removes conditional if for Swift 2
* Removes label from simulateTapOnTextViewForDelegate
* Audits open/public access levels
Adds more customizable options to the input bar
Bar with icons gets customizable height
Buttons get customizable intrinsic contentSize, so they can be bigger and easy to tap
Buttons get customizable images for any UIControlState
Send button gets customizable text colors for any UIControlState