Setup CI for foxi Project

[houseroad]

It will be useful signal for contributors.

[xsacha]

Just doing a simple build, I see a lot of missing ONNX related variables and I'm not sure how these would be filled out.
A CI configuration would help users understand this.

[sacha@localhost foxi]$ mkdir build
[sacha@localhost foxi]$ cd build
[sacha@localhost build]$ cmake .. -DCMAKE_BUILD_TYPE=Release -DCMAKE_INSTALL_PREFIX=./install
-- The C compiler identification is GNU 9.0.1
-- Check for working C compiler: /usr/bin/cc
-- Check for working C compiler: /usr/bin/cc -- works
-- Detecting C compiler ABI info
-- Detecting C compiler ABI info - done
-- Detecting C compile features
-- Detecting C compile features - done
-- 
-- ******** Summary ********
--   CMake version         : 3.13.4
--   CMake command         : /usr/bin/cmake
--   System                : Linux
--   C++ compiler          : 
--   C++ compiler version  : 
--   CXX flags             :  -Wnon-virtual-dtor
--   Build type            : Release
--   Compile definitions   : 
--   CMAKE_PREFIX_PATH     : 
--   CMAKE_INSTALL_PREFIX  : /home/sacha/dev/foxi/build/install
--   CMAKE_MODULE_PATH     : 
-- 
--   ONNX version          : 1.4.1
--   ONNX NAMESPACE        : 
--   ONNX_BUILD_TESTS      : 
--   ONNX_BUILD_BENCHMARKS : 
--   ONNX_USE_LITE_PROTO   : 
--   ONNXIFI_DUMMY_BACKEND : 
-- 
--   Protobuf compiler     : 
--   Protobuf includes     : 
--   Protobuf libraries    : 
--   BUILD_ONNX_PYTHON     : 
-- Configuring done
-- Generating done
-- Build files have been written to: /home/sacha/dev/foxi/build
[sacha@localhost build]$ make -j 4
Scanning dependencies of target foxi_dummy
Scanning dependencies of target foxi_loader
[ 16%] Building C object CMakeFiles/foxi_dummy.dir/foxi/onnxifi_dummy.c.o
[ 33%] Building C object CMakeFiles/foxi_loader.dir/foxi/onnxifi_loader.c.o
[ 50%] Linking C static library libfoxi_loader.a
[ 66%] Linking C shared library libfoxi_dummy.so
[ 66%] Built target foxi_loader
[ 66%] Built target foxi_dummy
Scanning dependencies of target foxi_wrapper
[ 83%] Building C object CMakeFiles/foxi_wrapper.dir/foxi/onnxifi_wrapper.c.o
[100%] Linking C shared module libfoxi.so
[100%] Built target foxi_wrapper
[sacha@localhost build]$ make -j 4 install
[ 33%] Built target foxi_dummy
[ 66%] Built target foxi_loader
[100%] Built target foxi_wrapper
Install the project...
-- Install configuration: "Release"
-- Installing: /home/sacha/dev/foxi/build/install/include/foxi
-- Installing: /home/sacha/dev/foxi/build/install/include/foxi/onnxifi_loader.h
-- Installing: /home/sacha/dev/foxi/build/install/include/foxi/onnxifi_ext.h
-- Installing: /home/sacha/dev/foxi/build/install/include/foxi/onnxifi.h
-- Installing: /home/sacha/dev/foxi/build/install/lib/libfoxi_dummy.so
-- Installing: /home/sacha/dev/foxi/build/install/lib/libfoxi_loader.a
-- Installing: /home/sacha/dev/foxi/build/install/lib/libfoxi.so

Also, no Config gets installed.