Fix deprecated jUnit imports and methods

I basically just replaced the deprecated `junit.framework.*` imports with `org.junit.*`.

The asertEquals(double, double) was also deprecated and throws AssertionError so I replaced that with assertEquals(double, double, double) where the last double represents the maximum delta between expected and actual value. I used the value 0.0 as that won't change the behavior of the tests and I am also not sure what the correct delta is.

All tests passed locally.