[Travis] Check code style before build (#1015)

.ci/travis/ubuntu/Dockerfile

@@ -29,6 +29,7 @@ COPY . /root/ngraph
 RUN mkdir /root/ngraph/build
 WORKDIR /root/ngraph/build
 RUN cmake ../ -DNGRAPH_USE_PREBUILT_LLVM=TRUE
+RUN make style-check
 RUN make -j 8
 RUN make install
 

.ci/travis/ubuntu/run_test.sh

@@ -4,7 +4,7 @@ set -e
 echo "TASK:" ${TASK}
 
 if [ ${TASK} == "cpp_test" ]; then
-    docker run -w '/root/ngraph/build' test_ngraph make style-check check
+    docker run -w '/root/ngraph/build' test_ngraph make check
 fi
 
 if [ ${TASK} == "python2_test" ]; then