generated test file, added asserts to collatz

wrote a 1000 line list of numbers to test the funciton with. added
asserts to check that the optimizations and features made previously
wont crash the program
created SphereCollatz added one optimization

added the n + (n//2) +1 optimization. this was enough to make
SphereCollatz get accepted.
adds cache to spherecollatzcache, readability changes

closes issue 19,