Docker build fails

The Dockerfile in master doesn't work.
```bash
/decord/src/video/ffmpeg/threaded_decoder.cc: In member function 'void decord::ffmpeg::FFMPEGThreadedDecoder::WorkerThread()':
/decord/src/video/ffmpeg/threaded_decoder.cc:176:26: warning: catching polymorphic type 'struct dmlc::Error' by value [-Wcatch-value=]
176 | } catch (dmlc::Error error) {
| ^~~~~
[ 72%] Building CXX object CMakeFiles/decord.dir/src/video/nvcodec/cuda_context.cc.o
[ 75%] Building CXX object CMakeFiles/decord.dir/src/video/nvcodec/cuda_decoder_impl.cc.o
[ 78%] Building CXX object CMakeFiles/decord.dir/src/video/nvcodec/cuda_mapped_frame.cc.o
[ 81%] Building CXX object CMakeFiles/decord.dir/src/video/nvcodec/cuda_parser.cc.o
[ 83%] Building CXX object CMakeFiles/decord.dir/src/video/nvcodec/cuda_stream.cc.o
[ 86%] Building CXX object CMakeFiles/decord.dir/src/video/nvcodec/cuda_texture.cc.o
[ 89%] Building CXX object CMakeFiles/decord.dir/src/video/nvcodec/cuda_threaded_decoder.cc.o
/decord/src/video/nvcodec/cuda_threaded_decoder.cc: In member function 'void decord::cuda::CUThreadedDecoder::LaunchThread()':
/decord/src/video/nvcodec/cuda_threaded_decoder.cc:304:24: warning: catching polymorphic type 'struct dmlc::Error' by value [-Wcatch-value=]
304 | } catch (dmlc::Error error) {
| ^~~~~
[ 91%] Building CXX object CMakeFiles/decord.dir/src/runtime/cuda/cuda_device_api.cc.o
[ 94%] Building CXX object CMakeFiles/decord.dir/src/runtime/cuda/cuda_module.cc.o
make[2]: *** No rule to make target '/usr/local/cuda/lib64/libnvcuvid.so', needed by 'libdecord.so'. Stop.
make[2]: *** Waiting for unfinished jobs....
[ 97%] Building CUDA object CMakeFiles/decord.dir/src/improc/improc.cu.o
make[1]: *** [CMakeFiles/Makefile2:76: CMakeFiles/decord.dir/all] Error 2
make: *** [Makefile:130: all] Error 2
The command '/bin/sh -c cd decord && mkdir build && cd build && cmake .. -DUSE_CUDA=ON -DCMAKE_BUILD_TYPE=Release && make -j2 && cd ../python && python3 setup.py install' returned a non-zero code: 2
```
Was this not tested?