stack can be undefined on uncaught exceptions causing TerminalReporter to throw

[catdad]

Sometimes (it is unclear to me when) uncaught exceptions that fail tests will not include a stack property. When this happens, the TerminalReporter throws an error. Worse, any reporters registered after the TerminalReporter are not notified of this failure, which is pretty bad.

My tests that repro this issue

describe('my tests', function() {
    it('throws async error', function () {
        setTimeout(function () {
            throw new Error('I am the error');
        }, 5);
    });

    it('just waits a bunch', function(done) {
        setTimeout(function () {
            done();
        }, 100);
    });
});

This throws an error here: https://github.com/larrymyers/jasmine-reporters/blob/491efaaafe97b7b02ab0788aeb41481cf345cd8e/src/terminal_reporter.js#L185

This should be an easy fix...

if (self.showStack && spec.failedExpectations[i].stack){