SoftwareTesting: Tests of itertools

done tests:

Name Who tested Black/White
count Tabea Black
zip_longest Tabea Black
accumulate Tabea Black
compress Iker Black
islice Iker Black
starmap Iker Black
Takewhile Kannan Black
Dropwhile Kannan Black
Chain.from_iterable Kannan Black
Combinations Borja Black and White
Combinations with replacement Borja Black
cycle Borja Black
Permutations Anwar Black
filterfalse Anwar Black
groupby Anwar Black
Repeat Julie Black
chain Julie Black
product Julie Black