Add the missing doc/requirements into running-tests.rst

tox command install dependencies from the ``requirements.txt``,
``test-requirements.txt`` and ``doc/requirements.txt`` files

Change-Id: Ie26c0eb42c128aa997b4255fcf7e7d0da015cb81

1 files changed, 3 insertions, 2 deletions

diff --git a/doc/source/contributor/running-tests.rst b/doc/source/contributor/running-tests.rst
index a793001b6..88b13feac 100644
--- a/doc/source/contributor/running-tests.rst
+++ b/doc/source/contributor/running-tests.rst
@@ -19,8 +19,9 @@ Preferred way to run the tests
 
 The preferred way to run the unit tests is using ``tox``. It executes tests in
 isolated environment, by creating separate virtualenv and installing
-dependencies from the ``requirements.txt`` and ``test-requirements.txt`` files,
-so the only package you install is ``tox`` itself:
+dependencies from the ``requirements.txt``, ``test-requirements.txt`` and
+``doc/requirements.txt`` files, so the only package you install is ``tox``
+itself:
 
 .. code-block:: console