add gitpod dockerfile to upgrade node and npm version

Signed-off-by: Augustin Husson <husson.augustin@gmail.com>

.gitpod.Dockerfile

@@ -0,0 +1,7 @@
+FROM gitpod/workspace-full
+
+ENV CUSTOM_NODE_VERSION=16
+
+RUN bash -c ". .nvm/nvm.sh && nvm install ${CUSTOM_NODE_VERSION} && nvm use ${CUSTOM_NODE_VERSION} && nvm alias default ${CUSTOM_NODE_VERSION}"
+
+RUN echo "nvm use default &>/dev/null" >> ~/.bashrc.d/51-nvm-fix