fatal error ，when excute make
**hello：when I try to intall this ,there is an error on progress 52% , can you help me?**
**[ ubuntu 16.04_x64 ]
[ openCV3.3.0 ]**
```
root@ubuntu:~/programs/opensse-master/release# make
[ 47%] Built target opensse
[ 52%] Building CXX object tools/CMakeFiles/vocabulary.dir/vocabulary.cpp.o
/home/yingshi/programs/opensse-master/tools/vocabulary.cpp:21:29: fatal error: opensse/opensse.h: No such file or directory
compilation terminated.
tools/CMakeFiles/vocabulary.dir/build.make:62: recipe for target 'tools/CMakeFiles/vocabulary.dir/vocabulary.cpp.o' failed
make[2]: *** [tools/CMakeFiles/vocabulary.dir/vocabulary.cpp.o] Error 1
CMakeFiles/Makefile2:150: recipe for target 'tools/CMakeFiles/vocabulary.dir/all' failed
make[1]: *** [tools/CMakeFiles/vocabulary.dir/all] Error 2
Makefile:127: recipe for target 'all' failed
make: *** [all] Error 2

```