Insufficient testing

[barkls]

It looks like the only test right now is for lattice_image.py, which isn't even used in the rest of the package. All of your functions should have tests that verify their output under all possible input scenarios. This will probably require you to break some functions up into smaller components (see #8).

[barkls]

Testing is still very inadequate. Take a look at the envypy and error correction groups' testing to get an idea of what we are looking for.

Writing good tests will require you to break up your long blocks of code into smaller functions that can be tested individually.