[Plume] Use latest base image while waiting for tag on Docker Hub

pica-plume/Dockerfile

-ARG VERSION=v0.5.0
+# Change as soon as the tag is published on Docker Hub :
+# https://hub.docker.com/r/plumeorg/plume/tags
+# For now 0.5.0 is not available
+ARG VERSION=latest
 FROM plumeorg/plume:${VERSION}
 
 ENV PLUME_VERSION=v0.5.0