[DOCKER] force copy for workspace in each child dockerfiles

Signed-off-by: Raphael Defosseux <raphael.defosseux@eurecom.fr>

docker/Dockerfile.eNB.ubuntu18

@@ -27,12 +27,13 @@
 
 FROM ran-build:latest AS enb-build 
 
+RUN rm -Rf /oai-ran
 WORKDIR /oai-ran
+COPY . .
 
 #run build_oai to build the target image
 RUN /bin/sh oaienv && \ 
     cd cmake_targets && \
-    rm -Rf log && \
     mkdir -p log && \
     ./build_oai --eNB --ninja -w USRP