Errors found in the `functions` notebook

[despadam]

[baffelli]

The exercise on converting units is using the wrong factor (10) instead of 1/10 to convert mm to cm.

[baffelli]

In the text we ask people to wirite a function called greet while the solution is called solution_greet

[despadam]

solution_summing_anything will sometimes fail on the third test even if we copy-paste the reference solution to it

[despadam]

The exercise on unit conversion tests for inches in the last test, even though this is not specified in the description