Fix at printing

Some stack traces have '[as X]' in them. So now the regexp checks the s[1]
  and the s[3] which means it captures the right line (my code) instead of
  printing tape's depth

at Test.user [as _cb] (/home/raynos/Documents/colingo-payments/test/integration/create-account.js:13:12)',
at Test.run (/home/raynos/Documents/colingo-payments/node_modules/tape/lib/test.js:53:14)',