Bump to node 13

pica-oh-my-form/Dockerfile

-FROM  node:10-alpine
+FROM  node:13-alpine
 LABEL maintainer="quentinduchemin@tuta.io"
 
 ARG OHMYFORM_VERSION=0.2.3
@@ -9,7 +9,7 @@ RUN addgroup --gid 9999 ohmyform && adduser -D --uid 9999 -G ohmyform ohmyform
 RUN apk add --no-cache python=2.7.16-r1 \
 	&& rm -rf /tmp/* \
 	&& npm install --quiet -g grunt@1.0.4 bower@1.8.8 pm2@3.5.1 \
-	&& npm cache clean
+	&& npm cache clean --force
 
 RUN wget -O omf.tar.gz https://github.com/ohmyform/ohmyform/archive/${OHMYFORM_VERSION}.tar.gz \
   && tar --strip-components=1 -x -f omf.tar.gz -C /opt/app \