build(cmake): use min CMake version prior to project call
The [CMake documentation](https://cmake.org/cmake/help/latest/command/cmake_minimum_required.html)
mandates that `cmake_minimum_required` should be called early
in the `CMakeLists.txt` prior to any `project()` command.
diff --git a/CMakeLists.txt b/CMakeLists.txt
index f111f1a..717f02e 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -12,11 +12,10 @@
# See the License for the specific language governing permissions and
# limitations under the License.
-cmake_policy(SET CMP0048 NEW)
-project(cppdap VERSION 1.59.0 LANGUAGES CXX C)
-
cmake_minimum_required(VERSION 3.13)
+project(cppdap VERSION 1.59.0 LANGUAGES CXX C)
+
set (CMAKE_CXX_STANDARD 11)
include(GNUInstallDirs)
