Updated code to import from future and use python 3 conventions
Removed tests for non-existent Observable and Config classes
Fixed integer division in twopoint get all momenta
Added build option to cmake code for python 3
Fixed bug in lattice get_link function.
Removed trailing whitespace from naik.cpp
Fixed set_config to load_config, as we're passing a filename in tests
Updated naik test data to reflect new action coefficients
Added python 3 cmake build messages
Fixed more compatability issues with python 3
Fixed more python 3 issues