[fix] Fix failed assertions output
[fix] Fix failed assertions output

Latest changes made to Vows in order to make it compatible with `node
v0.5.x` (see issue #141) introduce a bug which caused Vows to output
only file name and line when assertion fails:

    when testing
      ✗ should output details
        »  // test.js:8

This turned out to be a really small bug. Output works now:

    when testing
      ✗ should output details
        » expected { a: 1, b: 3 },
          got      { a: 1, b: 2 } (deepEqual) // test.js:8

Sorry for that.

MSOpenTech/vows