Complete a comphrensive set of UnitTest

[algebrato]

mapmaking/tests/test.rs

Line 11 in fcfc569

fn test_direcotry() {

A brief description of unit tests needed:

• Test the FloatingIterator
• Test the memory access of every thread
• Test the directory tree, and the distribution between the threads
• Test the binning algorithm with a dummy case
• Test the de-noise algorithm with a dummy case
• Test the downgrading algorithm (for maps, from nside 128 to lower)