Adding Week4 tests + sieveSundaram stub
added tests for localMaxima
toDigits and toDigitsRev impls
completion of exercises 1-4
hanoi implementation
improved doubleEveryOther impl
exercises 1-5, week 2
week 3: implementing 'skips' in terms of 'skip'
week 3: implementing 'localMaxima' in terms of 'chunk'
week 3: 'histogram' solution
fun1' impl
map' in terms of foldl
WIP: fun2'
foldl (*) 1 is the same as product
fun2' implementation
xor implementation
WIP
sieveSundaram impl