update parser to handle Specta 0.2.1

Specta 0.2.1 introduced indentation in the test output.

This commit updates the regexes for:

* FAILING_TEST_MATCHER
* TESTS_RUN_COMPLETION_MATCHER
* TESTS_RUN_START_MATCHER
* TEST_SUITE_START_MATCHER
* EXECUTED_MATCHER
* SAMPLE_SPECTA_TEST

To allow for optional whitespace at the start of the lines

Here's the output I get with the current xcpretty

![screen shot 2014-03-06 at 4 34 55 pm](https://f.cloud.github.com/assets/2799/2350985/2fffeb60-a577-11e3-8445-2ab89706aee7.png)

And the output with this PR

![screen shot 2014-03-06 at 4 37 46 pm](https://f.cloud.github.com/assets/2799/2351021/9b25f218-a577-11e3-9675-647984689ff4.png)

And here's a screenshot of some output without running through xcpretty

![screen shot 2014-03-06 at 4 39 06 pm](https://f.cloud.github.com/assets/2799/2351033/d98b05fc-a577-11e3-92af-d5081d91bacf.png)