Add sockpp, googletest and rapidjson

googletest/CMakeLists.txt

googletest/lib/.clang-format

googletest/lib/.github/ISSUE_TEMPLATE/00-bug_report.md

googletest/lib/.github/ISSUE_TEMPLATE/config.yml

googletest/lib/.gitignore

googletest/lib/.travis.yml

googletest/lib/BUILD.bazel

googletest/lib/CMakeLists.txt

googletest/lib/CONTRIBUTING.md

googletest/lib/CONTRIBUTORS

googletest/lib/LICENSE

googletest/lib/README.md

googletest/lib/WORKSPACE

googletest/lib/appveyor.yml

googletest/lib/ci/linux-presubmit.sh

googletest/lib/ci/macos-presubmit.sh

googletest/lib/docs/_config.yml

googletest/lib/docs/_data/navigation.yml

googletest/lib/docs/_layouts/default.html

googletest/lib/docs/_sass/main.scss