Tests/QtAutogen: Require CMake 3.1 to set policies everywhere

We want CMP0020 set in the autorcc_depends test.  Also the test should
now only run when we can support per-config source files.

Tests/QtAutogen/CMakeLists.txt

@@ -1,4 +1,4 @@
-cmake_minimum_required(VERSION 2.8.11)
+cmake_minimum_required(VERSION 3.1)
 
 project(QtAutogen)
 

Tests/QtAutogen/autorcc_depends/CMakeLists.txt

@@ -1,4 +1,4 @@
-cmake_minimum_required(VERSION 2.8)
+cmake_minimum_required(VERSION 3.1)
 project(autorcc_depends)
 
 set(CMAKE_AUTORCC ON)