Fix issues with angle, image path and error handling

[mollwe]

No description provided.

[peterekepeter]

Thank you very much man! I can't believe I left the test image hard-coded. I guess that what happens when you don't test things properly.

And thank you very much for the unit tests. 👍 👍 👍

[peterekepeter]

I've published on npm, I'm trying to see what I can do about coveralls so that travis build automatically does that too

[mollwe]

👍 Thanks for the quick update! ☺