Document fixes for lint errors

howto/code/lint/index.rst
howto/code/lint/fix-errors
--------------------------
  o Added a new 'fixing-errors' section in 'howto: lint'.

howto/code/lint/fix-errors/sphinx/spelling
howto/code/lint/fix-errors/yamllint
------------------------------------------
  o Document a few known fixes for common problems.

requirements.txt
----------------
  o Capture detail for a python upgrade error uncovered by 'make reload'.
  o libdoc command for robot/robotframework having issues.

Change-Id: Iaa700327d374b6040841cbfc98f76ba95c16c799
Signed-off-by: Joey Armstrong <jarmstrong@linuxfoundation.org>
diff --git a/VERSION b/VERSION
index 26340c0..a5c5ebd 100644
--- a/VERSION
+++ b/VERSION
@@ -1 +1 @@
-2.12.36
+2.12.37