Enforce iOS 11.0 after update from master

Author: thebluepotato

.travis.yml

@@ -4,7 +4,7 @@ osx_image: xcode9
 env:
   global:
     - IOS_SIMULATOR="iPhone 6s"
-    - IOS_VERSION="10.3.1"
+    - IOS_VERSION="11.0"
 matrix:
   include:
     - env: BUILD_SCHEME="SQLite iOS"