Fix missing dependency and add license files in Dockerfile (apache#1041)

Author: PragmaTwice

Dockerfile

@@ -30,6 +30,8 @@ RUN ./x.py build -DENABLE_OPENSSL=ON
 
 FROM ubuntu:focal
 
+RUN apt update && apt install -y libssl-dev
+
 WORKDIR /kvrocks
 
 COPY --from=build /kvrocks/build/kvrocks ./bin/
@@ -38,5 +40,8 @@ COPY ./kvrocks.conf  ./conf/
 RUN sed -i -e 's%dir /tmp/kvrocks%dir /var/lib/kvrocks%g' ./conf/kvrocks.conf
 VOLUME /var/lib/kvrocks
 
+COPY ./LICENSE ./NOTICE ./DISCLAIMER ./
+COPY ./licenses ./licenses
+
 EXPOSE 6666:6666
 ENTRYPOINT ["./bin/kvrocks", "-c", "./conf/kvrocks.conf"]