Install require packages:
npm install
Launch ganache blockchain with 10 accounts on port 8545:
ganache -a 10 -p 8545
You should see a blockchain server listening on 127.0.0.1:8545.
Next, open another terminal, run all tests (requries blockchain running on port 8545):
truffle test
You should see the gas cost for each transaction, and all 21 tests passing.