[IMP] administration/install, *: make 3.7 the minimum version for Python

As of commit https://github.com/odoo/odoo/commit/794677fb Python 3.7 is
the minimum required version for Python when running Odoo 15.0.

This also applies to building the version 15.0 of the documentation.

closes odoo/documentation#1218

Signed-off-by: Antoine Vandevenne (anv) <anv@odoo.com>

README.md

@@ -5,7 +5,7 @@
 ### Requirements
 
 - [Git](https://www.odoo.com/documentation/15.0/contributing/documentation.html#install-git)
-- [Python 3.6, 3.7, or 3.8](https://www.odoo.com/documentation/15.0/contributing/documentation.html#python)
+- [Python 3.7 or 3.8](https://www.odoo.com/documentation/15.0/contributing/documentation.html#python)
 - Python dependencies listed in the file [`requirements.txt`](https://github.com/odoo/documentation/tree/15.0/requirements.txt).
 - [Make](https://www.odoo.com/documentation/15.0/contributing/documentation.html#make)
 - A local copy of the [odoo/odoo repository in 15.0](https://github.com/odoo/odoo/tree/15.0) (Optional)

content/administration/install/install.rst

@@ -302,13 +302,13 @@ Prepare
 Python
 ^^^^^^
 
-Odoo requires Python 3.6 or later to run. Visit `Python's download page <https://www.python.org/downloads/windows/>`_
+Odoo requires Python 3.7 or later to run. Visit `Python's download page <https://www.python.org/downloads/windows/>`_
 to download and install the latest version of Python 3 on your machine.
 
 During installation, check **Add Python 3 to PATH**, then click **Customize Installation** and make
 sure that **pip** is checked.
 
-.. note:: If Python 3 is already installed, make sure that the version is 3.6 or above, as previous
+.. note:: If Python 3 is already installed, make sure that the version is 3.7 or above, as previous
           versions are not compatible with Odoo.
 
           .. code-block:: doscon
@@ -466,10 +466,10 @@ Prepare
 Python
 ^^^^^^
 
-Odoo requires Python 3.6 or later to run. Use your package manager to download and install Python 3
+Odoo requires Python 3.7 or later to run. Use your package manager to download and install Python 3
 on your machine if it is not already done.
 
-.. note:: If Python 3 is already installed, make sure that the version is 3.6 or above, as previous
+.. note:: If Python 3 is already installed, make sure that the version is 3.7 or above, as previous
           versions are not compatible with Odoo.
 
           .. code-block:: console
@@ -635,10 +635,10 @@ Prepare
 Python
 ^^^^^^
 
-Odoo requires Python 3.6 or later to run. Use your preferred package manager (homebrew_, macports_)
+Odoo requires Python 3.7 or later to run. Use your preferred package manager (homebrew_, macports_)
 to download and install Python 3 on your machine if it is not already done.
 
-.. note:: If Python 3 is already installed, make sure that the version is 3.6 or above, as previous
+.. note:: If Python 3 is already installed, make sure that the version is 3.7 or above, as previous
           versions are not compatible with Odoo.
 
           .. code-block:: console

content/developer/howtos/rdtraining/01_architecture.rst

@@ -131,7 +131,7 @@ to make sure we start on the same page during the development of our new applica
     https://en.wikipedia.org/wiki/Multitier_architecture
 
 .. _Python tutorial:
-    https://docs.python.org/3.6/tutorial/
+    https://docs.python.org/3.7/tutorial/
 
 .. _two versions:
     https://www.odoo.com/page/editions

content/developer/howtos/rdtraining/02_setup.rst

@@ -161,7 +161,7 @@ Install the dependencies
 Python
 ------
 
-Odoo requires Python 3.6 or later, if your computer is up-to-date you should already be at this
+Odoo requires Python 3.7 or later, if your computer is up-to-date you should already be at this
 version or higher.
 
 You can check your Python version with: