fix include paths to make the 'cargo test' pass

[tronch0]

keep getting no such file or directory error message.

ron-x1➜  rust : master ✘ :✹✭ ᐅ  cargo test
   Compiling zkstandard v0.1.0 (/home/ron/qed-it/gadget_standard/rust)
error: failed to run custom build command for `zkstandard v0.1.0 (/home/ron/qed-it/gadget_standard/rust)`
process didn't exit successfully: `/home/ron/qed-it/gadget_standard/rust/target/debug/build/zkstandard-5173a8be719ffbcd/build-script-build` (exit code: 101)
--- stdout
running: "cmake" "/home/ron/qed-it/gadget_standard/rust/../cpp" "-DCMAKE_INSTALL_PREFIX=/home/ron/qed-it/gadget_standard/rust/target/debug/build/zkstandard-22e656ac751e03e9/out" "-DCMAKE_C_FLAGS= -ffunction-sections -fdata-sections -fPIC -m64" "-DCMAKE_C_COMPILER=/usr/bin/cc" "-DCMAKE_CXX_FLAGS= -ffunction-sections -fdata-sections -fPIC -m64" "-DCMAKE_CXX_COMPILER=/usr/bin/c++" "-DCMAKE_BUILD_TYPE=Debug"
-- Configuring done
-- Generating done
-- Build files have been written to: /home/ron/qed-it/gadget_standard/rust/target/debug/build/zkstandard-22e656ac751e03e9/out/build
running: "cmake" "--build" "." "--target" "install" "--config" "Debug" "--"
Scanning dependencies of target zkcomponent
[ 50%] Building CXX object CMakeFiles/zkcomponent.dir/gadget.cpp.o
CMakeFiles/zkcomponent.dir/build.make:62: recipe for target 'CMakeFiles/zkcomponent.dir/gadget.cpp.o' failed
CMakeFiles/Makefile2:67: recipe for target 'CMakeFiles/zkcomponent.dir/all' failed
Makefile:127: recipe for target 'all' failed

--- stderr
In file included from /home/ron/qed-it/gadget_standard/cpp/flatbuffers/flatbuffers.h:20:0,
                 from /home/ron/qed-it/gadget_standard/cpp/gadget_generated.h:7,
                 from /home/ron/qed-it/gadget_standard/cpp/gadget.cpp:2:
/home/ron/qed-it/gadget_standard/cpp/flatbuffers/base.h:54:39: fatal error: flatbuffers/stl_emulation.h: No such file or directory
compilation terminated.
make[2]: *** [CMakeFiles/zkcomponent.dir/gadget.cpp.o] Error 1
make[1]: *** [CMakeFiles/zkcomponent.dir/all] Error 2
make: *** [all] Error 2
thread 'main' panicked at '
command did not execute successfully, got: exit code: 2

build script failed, must exit now', /home/ron/.cargo/registry/src/github.com-1ecc6299db9ec823/cmake-0.1.35/src/lib.rs:778:5
note: Run with `RUST_BACKTRACE=1` for a backtrace.

after changing the include paths:

ron-x1➜  rust : master ✘ :✹✭ ᐅ  cargo test
   Compiling zkstandard v0.1.0 (/home/ron/qed-it/gadget_standard/rust)
    Finished dev [unoptimized + debuginfo] target(s) in 1.85s
     Running target/debug/deps/zkstandard-1fb700eca3bcaa0f

running 1 test
C++ got R1CS request, name=sha256, free_variable_id_before=103
C++ got assignment request, name=sha256, free_variable_id_before=103
test gadget_call::test_gadget_request ... ok

test result: ok. 1 passed; 0 failed; 0 ignored; 0 measured; 0 filtered out

   Doc-tests zkstandard

running 0 tests

test result: ok. 0 passed; 0 failed; 0 ignored; 0 measured; 0 filtered out

[naure]

Does it work for you after merging #2 ?