Sort imports with isort

Keep imports alphabetically sorted and their order homogeneous across
Python source files.

The isort project has more feature and is more active than the
flake8-import-order plugin.

Most issues caught were simply import ordering from the same module.
Where imports were purposefully placed out of order, tag with
isort:skip.

1 files changed, 4 insertions, 3 deletions

diff --git a/setup.py b/setup.py
index 27bbb3ae0..ca08a6d4a 100644
--- a/setup.py
+++ b/setup.py
@@ -43,7 +43,7 @@ extras_require = {
     ],
     'lint': [
         'flake8>=3.5.0',
-        'flake8-import-order',
+        'isort',
         'mypy>=0.790',
         'docutils-stubs',
     ],
@@ -76,9 +76,10 @@ class Tee:
 
 
 try:
-    from babel.messages.pofile import read_po
-    from babel.messages.frontend import compile_catalog
     from json import dump
+
+    from babel.messages.frontend import compile_catalog
+    from babel.messages.pofile import read_po
 except ImportError:
     pass
 else: