add --force flag

Author: alejandroSuch

Dockerfile

@@ -6,6 +6,6 @@ RUN apk update \
   && yarn global add @angular/cli@1.4.3 \
   && ng set --global packageManager=yarn \
   && rm -rf /tmp/* /var/cache/apk/* *.tar.gz ~/.npm \
-  && npm cache clear \
+  && npm cache clear --force \
   && yarn cache clean \
   && sed -i -e "s/bin\/ash/bin\/sh/" /etc/passwd