"fix unrar in docker"

Dockerfile

@@ -25,7 +25,7 @@ COPY ./paddle/scripts/docker/root/ /root/
 RUN apt-get update && \
     apt-get install -y \
     git python-pip python-dev openssh-server bison  \
-    wget unzip tar xz-utils bzip2 gzip coreutils ntp \
+    wget unzip unrar tar xz-utils bzip2 gzip coreutils ntp \
     curl sed grep graphviz libjpeg-dev zlib1g-dev  \
     python-numpy python-matplotlib gcc g++ \
     automake locales clang-format-3.8 swig doxygen cmake  \