Add 'signup_tests/' from commit '93fd25cb72e612bfc5ada4f4661eb47ac6029684'

git-subtree-dir: signup_tests
git-subtree-mainline: 93fd25cb72e612bfc5ada4f4661eb47ac6029684
git-subtree-split: 93fd25cb72e612bfc5ada4f4661eb47ac6029684