Storyboard enum cases should always be camelCase

[aspyre]

As per the Swift 3 guidelines, the enum cases should always start with a lowercase letter, rather than using the casing provided by the identifier.

[phimage]

Two things to do

• edit Parser and modify ReusableKind, SegueKind generated code with a lowercase letter
• edit Storyboard and look for enum Segue, to modify code which call SwiftRepresentationForString, to ask this function to set update the first letter to lowercase(there is already a capitalizeFirstLetter parameter that could be replaced by a clean enum firstLetter: .capitalize or .lowercase or .none by default )

I can do it if my PR #96 is merged, because I edit SwiftRepresentationForString, so a conflict will occurs

[aspyre]

Thank you!