Install googletest

sudo apt-get install libgtest-dev
cd /usr/src/googletest/googletest
sudo mkdir build
cd build
sudo cmake ..
sudo make
sudo cp libgtest* /usr/lib/
cd ..
sudo rm -rf build

sudo mkdir /usr/local/lib/googletest
sudo ln -s /usr/lib/libgtest.a /usr/local/lib/googletest/libgtest.a
sudo ln -s /usr/lib/libgtest_main.a /usr/local/lib/googletest/libgtest_main.a