tests: don't use a hard-coded date in isPastDate validator

[BrunoRosendo]

In the following validator function, we use a hard-coded string with a date in the year "3000" to simulate a date in the future:

website-niaefeup-backend/src/test/kotlin/pt/up/fe/ni/website/backend/controller/ValidationTester.kt

Line 120 in 823edf9

params[param] = "01-01-3000" // TODO: use a date in the future instead of hard coded

It would be best to replace this with some logic that takes the current date and adds a day, for example.

PS: This way the tests won't break when we get to 3001 :p