Automatically sort Python imports in code.

NEWS

@@ -4,6 +4,7 @@
  * Document installing borgmatic with pip install --user instead of a system Python install.
  * Get more reproducible builds by pinning the versions of pip and tox used to run tests.
  * Factor out build/test configuration from tox.ini file.
+ * Automatically sort Python imports in code.
 
 1.3.3
  * Add validate-borgmatic-config command, useful for validating borgmatic config generated by