.flake8: add config file for Python code style

We recommend wrapping at 80 columns but we accept 132 columns when it
makes more readable.

Follow up of discussion at this thread:
http://lists.busybox.net/pipermail/buildroot/2017-October/203624.html

Cc: Arnout Vandecappelle <[email protected]>
Cc: Peter Korsgaard <[email protected]>
Cc: Thomas Petazzoni <[email protected]>
Cc: Yann E. MORIN <[email protected]>
Signed-off-by: Ricardo Martincoski <[email protected]>
Signed-off-by: Arnout Vandecappelle (Essensium/Mind) <[email protected]>

Author: ricardo-martincoski

Diff for: .flake8

@@ -0,0 +1,2 @@
+[flake8]
+max-line-length=132