Failing Build (Linux)

I am trying to build on Linux (Ubuntu) but I am getting the following error

```
make[1]: Entering directory '/bc-lifehash-cli/src'
rm -f lifehash *.o
rm -rf *.dSYM
make[1]: Leaving directory '/bc-lifehash-cli/src'
cd src && make lifehash
make[1]: Entering directory '/bc-lifehash-cli/src'
g++ -O3 -std=c++17 -I/bc-lifehash-cli/sysroot/include -I/bc-lifehash-cli/sysroot/include -c -o lifehash.o lifehash.cpp
lifehash.cpp:11:10: fatal error: lifehash/lifehash.hpp: No such file or directory
11 | #include
| ^~~~~~~~~~~~~~~~~~~~~~~
compilation terminated.
make[1]: *** [: lifehash.o] Error 1
make[1]: Leaving directory '/bc-lifehash-cli/src'
make: *** [Makefile:20: lifehash] Error 2
```

Steps to replicate:
`$ git clone https://github.com/BlockchainCommons/bc-lifehash-cli`
`$ cd bc-lifehash-cli/`
`$ ./build.sh`
> This is where the above error occurs