Colorize JSCS error description output

Passing "true" to explainError causes JSCS to colorize the error
description, improving the readability of the module's output.

Removed ' at' from the test string it is not necessary for
verifying the behavior and the error text is colored differently
from the "at" text, preventing a straight text match.
Merge pull request #8 from kadamwhite/colorize-output

Colorize JSCS error description output