Add Travis testing on CentOS (#914)

* Add Travis testing on CentOS
* Disable building CPU Backend
* Remove Python dependencies from CentOS for now

.ci/travis/centos/Dockerfile

+FROM centos:7
+
+RUN yum -y update && \
+    yum -y --enablerepo=extras install epel-release && \
+    yum -y install \
+    gcc gcc-c++ \
+    cmake3 make \
+    git \
+    curl unzip \
+    autoconf automake autogen libtool \
+    wget patch diffutils zlib-devel ncurses-devel \
+    python python-devel python-setuptools \
+    doxygen graphviz \
+    which \
+    'perl(Data::Dumper)'
+
+RUN ln -s /usr/bin/cmake3 /usr/bin/cmake
+
+RUN cmake --version
+RUN make --version
+RUN gcc --version
+RUN c++ --version
+
+# Install nGraph in /root/ngraph
+COPY . /root/ngraph
+RUN mkdir /root/ngraph/build
+WORKDIR /root/ngraph/build
+
+RUN cmake .. -L -DNGRAPH_CPU_ENABLE=FALSE -DNGRAPH_ONNX_IMPORT_ENABLE=TRUE -DCMAKE_INSTALL_PREFIX="~/ngraph_dist"
+
+RUN make -j"$(nproc)"
+RUN make install
+
+CMD cd /root/ngraph/build && make unit-test-check

.travis.yml

@@ -9,22 +9,23 @@ git:
   depth: false
 
 env:
-  - TASK=cpp_test
-  - TASK=python2_test
-  - TASK=python3_test
+  - TASK=cpp_test OS=ubuntu
+  - TASK=cpp_test OS=centos
+  - TASK=python2_test OS=ubuntu
+  - TASK=python3_test OS=ubuntu
 
 before_install:
   - |
-    if [ "TASK" == "cpp_test" ]; then 
-      docker build -t test_ngraph -f .ci/travis/ubuntu/Dockerfile .
+    if [ "TASK" == "cpp_test" ]; then
+      docker build -t test_ngraph -f .ci/travis/$OS/Dockerfile .
     else
-      docker build -t test_ngraph -f .ci/travis/ubuntu/Dockerfile --build-arg buildtype=interpreter .
+      docker build -t test_ngraph -f .ci/travis/$OS/Dockerfile --build-arg buildtype=interpreter .
     fi
 
 install: true
 
 script:
-  - .ci/travis/ubuntu/run_test.sh
+  - .ci/travis/run_test.sh
 
 branches:
   only: