Check for .flake8 after importing flake8

This way, tests won't fail if both the flake8 module and the .flake8 file are missing.

Author: Robert Schütz

tests/test__sourcecode.py

@@ -17,16 +17,16 @@ def find_root():
 class TestFlake8(unittest.TestCase):
 
     def test_flake8(self):
-        root_path = find_root()
-        config_path = os.path.join(root_path, '.flake8')
-        if not os.path.exists(config_path):
-            raise RuntimeError('could not locate .flake8 file')
-
         try:
             import flake8  # NoQA
         except ImportError:
             raise unittest.SkipTest('flake8 module is missing')
 
+        root_path = find_root()
+        config_path = os.path.join(root_path, '.flake8')
+        if not os.path.exists(config_path):
+            raise RuntimeError('could not locate .flake8 file')
+
         try:
             subprocess.run(
                 [sys.executable, '-m', 'flake8', '--config', config_path],