python: document python-save-before-test

layers/+lang/python/README.org

@@ -12,6 +12,7 @@
     - [[#syntax-checking][Syntax checking]]
   - [[#test-runner][Test runner]]
   - [[#automatic-buffer-formatting-on-save][Automatic buffer formatting on save]]
+  - [[#automatic-save-of-buffer-when-testing][Automatic save of buffer when testing]]
   - [[#autoflake][autoflake]]
   - [[#pylookup][pylookup]]
   - [[#hy-mode][Hy-mode]]
@@ -120,6 +121,15 @@ To enable automatic buffer formatting on save with  [[https://github.com/google/
     (python :variables python-enable-yapf-format-on-save t)))
 #+END_SRC
 
+** Automatic save of buffer when testing
+By default a buffer is automatically saved before tests are executed upon it,
+you can disable this feature by setting =python-save-before-test= to =nil=.
+
+#+BEGIN_SRC emacs-lisp
+  (setq-default dotspacemacs-configuration-layers '(
+    (python :variables python-save-before-test nil)))
+#+END_SRC
+
 ** autoflake
 To be able to suppress unused imports easily, install [[https://github.com/myint/autoflake][autoflake]]: