Update deployment instructions for Python 3

Signed-off-by: Roberto Rosario <roberto.rosario@mayan-edms.com>

docs/chapters/deploying.rst

@@ -29,7 +29,7 @@ For another setup that offers more performance and scalability refer to the
 
        sudo apt-get install g++ gcc ghostscript gnupg1 graphviz libfuse2 \
        libjpeg-dev libmagic1 libpq-dev libpng-dev libreoffice libtiff-dev \
-       poppler-utils postgresql python-dev python-virtualenv redis-server \
+       poppler-utils postgresql python3-dev python3-virtualenv redis-server \
        sane-utils supervisor tesseract-ocr zlib1g-dev -y
 
    .. note::
@@ -63,7 +63,7 @@ For another setup that offers more performance and scalability refer to the
    of the Python packages in the system.
    ::
 
-       sudo virtualenv /opt/mayan-edms
+       sudo virtualenv /opt/mayan-edms -p /usr/bin/python3
 
 
 5. Make the mayan user the owner of the installation directory:

docs/releases/3.3.rst

@@ -130,9 +130,14 @@ Upgrading from a previous version
 If installed via Python's PIP
 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
+Update the virtualenv to Python 3::
+
+    sudo -u mayan virtualenv /opt/mayan-edms -p /usr/bin/python3
+
 Remove deprecated requirements::
 
-    sudo -u mayan curl https://gitlab.com/mayan-edms/mayan-edms/raw/master/removals.txt -o /tmp/removals.txt && sudo -u mayan /opt/mayan-edms/bin/pip uninstall -y -r /tmp/removals.txt
+    sudo -u mayan curl https://gitlab.com/mayan-edms/mayan-edms/raw/master/removals.txt -o /tmp/removals.txt \
+    && sudo -u mayan /opt/mayan-edms/bin/pip uninstall -y -r /tmp/removals.txt
 
 Type in the console::
 

docs/topics/faq.rst

@@ -207,8 +207,23 @@ apparent reason.
 Does Mayan EDMS work with Python 3?
 -----------------------------------
 
-Yes but it is not production ready yet. Users are encouraged to deploy test
-installations of Mayan EDMS on Python 3 and report findings.
+Yes, version 3.3 ships with Python 3.7 support. Support for Python 2 will
+be removed in version 4.0.
+
+How to upgrade an existing Python 2 virtualenv
+----------------------------------------------
+
+Use::
+
+    virtualenv <existing directory> -p <Python 3 binary path>
+
+If you followed the deployment instructions, the command line would be::
+
+    virtualenv /opt/mayan-edms -p /usr/bin/python3
+
+If using a dedicated user account for Mayan EDMS::
+
+    sudo -u <username> virtualenv /opt/mayan-edms -p /usr/bin/python3
 
 
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