Handle numerical issues complex_numbers_spec.cr

[f-fr]

The spec uses eq to test for equality of complex numbers. However, the real and imaginary parts are Float64, hence there might be numerical issues. Instead, the be_close expectation should be used.

Using eq would require the Complex class to be modified (e.g. by overloading == to be slightly imprecise). But this would somehow hard-code the precision of Complex, which would not be a good idea if Complex was a "production" implementation. Although it is only an exercise, it should not encourage "bad style" like this.

[ryanplusplus]

The changes look good but they need to be done in the test template because the tests aren't generated instead of manually written.

[ryanplusplus]

Make these changes in exercises/practice/complex-numbers/.meta/test_template.ecr

[f-fr]

I could also modify the example solution and remove the == operator (it is not needed anymore).

[ryanplusplus]

I could also modify the example solution and remove the == operator (it is not needed anymore).

Yes please