Update README.md

"punch in/out" seems is most widely used than "clock in/out"
Specify versions for some gems and change RSpec for Minitest.
Set up test simple test environment with Minitest.
Secret option provided to Rack::Session::Cookie.
Fix ambiguos expression in conditional (change = by ==).
Add Modules and wraps some dependencies in our own classes.
Add tests for the OmniAuth wrapper.
Add first models.
Replace explicit queries by models.
Set up Minitest with Guard and reorganize the test structure.
Add migrations to create the partioned schema for registers.
Remove explicit checking for uniqueness violation when creating new user.