Fix RTL supports within UIScrollView

LayoutKit.podspec

@@ -9,6 +9,7 @@ Pod::Spec.new do |spec|
   spec.source_files      = 'Sources/**/*.swift'
   spec.documentation_url = 'http://layoutkit.org'
 
+  spec.swift_versions = ['5']
   spec.ios.deployment_target = '8.0'
   spec.ios.frameworks        = 'Foundation', 'CoreGraphics', 'UIKit'
   spec.ios.exclude_files     = [

Sources/LayoutArrangement.swift

@@ -7,7 +7,7 @@
 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 
 import CoreGraphics
-
+import UIKit
 /**
  The frame of a layout and the frames of its sublayouts.
  */
@@ -115,8 +115,12 @@ public struct LayoutArrangement {
 
     /// Flips the right and left edges of the view's subviews.
     private func flipSubviewsHorizontally(_ view: View) {
+        var width = view.bounds.width
+        if let scrollView = view as? UIScrollView {
+            width = scrollView.contentSize.width
+        }
         for subview in view.subviews {
-            subview.frame.origin.x = view.frame.width - subview.frame.maxX
+            subview.frame.origin.x = width - subview.frame.maxX
             flipSubviewsHorizontally(subview)
         }
     }