This directory contains external projects, taken from the following locations:
scrypt: http://www.tarsnap.com/scrypt.html
gtest: https://github.com/google/googletest
spdlog: https://github.com/gabime/spdlog/commit/0c7beb2e36008598cf80d0e8eb8635ac403febb9 (commit 0c7beb2e36008598cf80d0e8eb8635ac403febb9)