[!347] Force Python interpreter version to be major version 3

Merge branch 'feature/remove-python2-support' into 'master'

See merge request [extensions/dune-codegen!347]

  [extensions/dune-codegen!347]: Noneextensions/dune-codegen/merge_requests/347

CMakeLists.txt

@@ -21,6 +21,8 @@ set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -DDUNE_ISTL_SUPPORT_OLD_CATEGORY_INTERFA
 # start a dune project with information from dune.module
 dune_project()
 
+dune_python_force_version(3)
+
 dune_add_library(dunecodegen dune/codegen/common/tsc.cc)
 
 dune_target_enable_all_packages(dunecodegen)

python/setup.py

@@ -29,6 +29,7 @@ setup(name='dune.codegen',
       description='Performance optimizing form compiler for the Dune project',
       author='Dominic Kempf <dominic.kempf@iwr.uni-heidelberg.de>',
       url='https://gitlab.dune-project.org/dominic/dune-codegen.git',
+      python_requires='>=3',
       packages=['dune.codegen',
                 'dune.codegen.blockstructured',
                 'dune.codegen.cgen',