[cmake_format] bump min version, add command lowercasing

.cmake_format.py

@@ -36,4 +36,6 @@ enum_char = '.'
 # What style line endings to use in the output.
 line_ending = 'unix'
 
-# Specify structure for custom cmake functions
+# Format command names with this case. Options are "lower", "upper",
+# "unchanged"
+command_case = u'lower'

python/setup.py

@@ -27,7 +27,7 @@ setup(name='dune.xt.common',
       zip_safe = 0,
       package_data = {'': ['*.so']},
       install_requires=['binpacking==1.3', 'cython', 'jinja2', 'docopt', 'pylicense3>=0.2.1',
-                        'ipython', 'pytest', 'pytest-cov', 'cmake_format'],
+                        'ipython', 'pytest', 'pytest-cov', 'cmake_format>=0.3.6'],
       scripts=['./scripts/generate_compare_functions.py',
                './scripts/distribute_testing.py',
                './scripts/dxt_code_generation.py',