Show tracebacks from tape-catch

[Wilfred]

Given the following JS:

import test from 'tape-catch';

test('No such variable', t => {
  foo
});

The package tape-catch uses the following tap structure:

TAP version 13
# No such variable
not ok 1 ReferenceError: foo is not defined
  ---
    operator: error
    expected: |-
      undefined
    actual: |-
      [ReferenceError: foo is not defined]
    at: Test.exports.Test.run (/users/is/whughes/workspace/grail/node_modules/tape-catch/index.js:29:10)
    stack: |-
      ReferenceError: foo is not defined
          at Test.<anonymous> (/users/is/whughes/workspace/grail/static/__tests__/foo-test.js:4:3)
          at Test.bound [as _cb] (/users/is/whughes/workspace/grail/node_modules/tape/lib/test.js:65:32)
          at Test.exports.Test.run (/users/is/whughes/workspace/grail/node_modules/tape-catch/index.js:26:10)
          at Test.bound [as run] (/users/is/whughes/workspace/grail/node_modules/tape/lib/test.js:65:32)
          at Immediate.next (/users/is/whughes/workspace/grail/node_modules/tape/lib/results.js:71:15)
          at runCallback (timers.js:574:20)
          at tryOnImmediate (timers.js:554:5)
          at processImmediate [as _immediateCallback] (timers.js:533:5)
  ...

1..1
# tests 1
# pass  0
# fail  1

Currently tap-diff is suppressing this traceback.