[IMP] use python3.8 for pre-commit-vauxoo

Closes Vauxoo#203.

pre-commit-vauxoo requires Python 3.7 or greater to run. Some containers
in Odoo 12 and below are using Python 3.6, as a workaround, if the
Python version detected is not suitable, Python 3.8 will be installed
and used for running pre-commit-vauxoo.

src/travis2docker/templates/Dockerfile_deployv

@@ -24,6 +24,7 @@ ENV {{ build_env_arg }}=TRUE
 # Create cluster with odoo as owner and use environment variables instead of odoo cfg to connect
 RUN . /home/odoo/build.sh && \
     install_dev_tools && \
+    install_pcv && \
     service_postgres_without_sudo odoo odoo && \
     install_pgcli_venv && \
     custom_alias && \

src/travis2docker/templates/build.sh

@@ -103,19 +103,11 @@ install_dev_tools(){
         py-spy \
         virtualenv \
         ipdb \
-        pre-commit-vauxoo \
         diff-highlight \
         pg-activity \
         nodeenv \
         pdbpp
 
-    # Symlinks used by vscode and possibly other tools.
-    PCV_DIR="$(python3 -c "import pre_commit_vauxoo as pcv; print(pcv.__path__[0])")/cfg"
-    ln -sf "${PCV_DIR}/.pylintrc" "${HOME}/.pylintrc"
-    ln -sf "${PCV_DIR}/.flake8" "${HOME}/.flake8"
-    ln -sf "${PCV_DIR}/.isort.cfg" "${HOME}/.isort.cfg"
-    ln -sf "${PCV_DIR}/.eslintrc.json" "${HOME}/.eslintrc.json"
-
     # pre install pre-commit-vauxoo?
     # sudo su odoo -c "git init /tmp/test && cd /tmp/test && pre-commit-vauxoo -f"
     touch /home/odoo/full_test-requirements.txt
@@ -153,6 +145,28 @@ EOF
     git clone --depth 1 -b master https://github.com/Vauxoo/emacs.d.git /home/odoo/.emacs.d
 }
 
+# Ensure pre-commit-vauxoo is installed on python3.8
+install_pcv() {
+    [[ $(python3 --version) =~ [0-9]\.([0-9]+) ]]
+
+    if ! [[ ${BASH_REMATCH[1]} -lt 7 ]]; then
+        printf "INFO: Using python <= 3.7, installing python3.8 for pcv\n"
+        PYTHON=python3.8
+        apt install ${PYTHON} -y
+        curl -sSL https://bootstrap.pypa.io/get-pip.py | ${PYTHON} -
+    else
+        PYTHON=python3
+    fi
+    ${PYTHON} -m pip install pre-commit-vauxoo
+
+    # Symlinks used by vscode and possibly other tools.
+    PCV_DIR="$(${PYTHON} -c "import pre_commit_vauxoo as pcv; print(pcv.__path__[0])")/cfg"
+    ln -sf "${PCV_DIR}/.pylintrc" "${HOME}/.pylintrc"
+    ln -sf "${PCV_DIR}/.flake8" "${HOME}/.flake8"
+    ln -sf "${PCV_DIR}/.isort.cfg" "${HOME}/.isort.cfg"
+    ln -sf "${PCV_DIR}/.eslintrc.json" "${HOME}/.eslintrc.json"
+}
+
 setup_coverage() {
   echo "export MODULES2TEST=$(cd ${MAIN_REPO_FULL_PATH} && find * -name "__manifest__.py" -printf "/%h,")" >> ${HOME}/.bashrc
   echo "export MODULES2INSTALL=$(cd ${MAIN_REPO_FULL_PATH} && find * -name "__manifest__.py" -printf "%h,")" >> ${HOME}/.bashrc