Updates travis.yml

Author: simonmitchell

.travis.yml

@@ -1,13 +1,13 @@
 language: swift
 xcode_project: ThunderBasics.xcodeproj # path to your xcodeproj folder
-osx_image: xcode11
+osx_image: xcode11.6
 env:
   global:
   - LC_CTYPE=en_US.UTF-8
   - LANG=en_US.UTF-8
 matrix:
   include:
     - xcode_scheme: ThunderBasics-iOS
-      xcode_destination: platform=iOS Simulator,OS=13.0,name=iPhone 11 Pro Max
+      xcode_destination: platform=iOS Simulator,OS=13.6,name=iPhone 11 Pro Max
     - xcode_scheme: ThunderBasics-macOS
       xcode_destination: platform=macOS