Added RequestException. It is thrown when request fails.
Merge https://github.com/pdt256/shipping into exceptions
Merge pull request #6 from perk11/exceptions

Thanks Konstantin!
Migrating code to PSR2. Adding optional support for live API calls in unit tests. Adding rounding error bug fix. Adding more tests to get to 85% coverage. Adding phpstorm project. Bumping master for v1.0.x target.
Update README.md
Fixing phpstorm project files.
Merge https://github.com/pdt256/shipping