Fix clang format docker

templates/tools/dockerfile/test/sanity/Dockerfile.template

@@ -54,6 +54,8 @@
   RUN ./bazel-0.4.4-installer-linux-x86_64.sh
   
   <%include file="../../clang5.include"/>
+  RUN ln -s /clang+llvm-5.0.0-linux-x86_64-ubuntu14.04/bin/clang-format /usr/local/bin/clang-format
+  ENV CLANG_FORMAT=clang-format
   <%include file="../../run_tests_addons.include"/>
   
   # Define the default command.

tools/dockerfile/test/sanity/Dockerfile

@@ -109,6 +109,8 @@ RUN apt-get update && apt-get -y install wget xz-utils
 RUN wget http://releases.llvm.org/5.0.0/clang+llvm-5.0.0-linux-x86_64-ubuntu14.04.tar.xz
 RUN tar xf clang+llvm-5.0.0-linux-x86_64-ubuntu14.04.tar.xz
 
+RUN ln -s /clang+llvm-5.0.0-linux-x86_64-ubuntu14.04/bin/clang-format /usr/local/bin/clang-format
+ENV CLANG_FORMAT=clang-format
 # Prepare ccache
 RUN ln -s /usr/bin/ccache /usr/local/bin/gcc
 RUN ln -s /usr/bin/ccache /usr/local/bin/g++