Word failure used instead of error, potential confusion

[VikiAnn]

This may be too nitpicky, but I'm going through the tutorial again as a sort of guide as I try and do the report card practice, and I noticed where it says "Run the test again, and get a failure:" it's actually referring to an error, not a failure, and since the point was made that errors and failures are different things, I thought maybe that should be changed to error.

[kytrinyx]

Excellent point, thanks for catching this! I try to be very specific about which is which, but sometimes I get them messed up (sloppy language -> sloppy thinking).