PEP8 fixes on setup.py
Add nose, coverage and tox on requirements
PEP8 fixes on tests/tya_test.py
PEP8 fixes on tests/txa_test.py
PEP8 fixes on tests/tsx_test.py
PEP8 fixes on tests/tay_test.py
PEP8 fixes on tests/tax_test.py
PEP8 fixes on tests/sty_test.py
PEP8 fixes on tests/stx_test.py
PEP8 fixes on tests/sta_test.py
PEP8 fixes on tests/spriteset_test.py
PEP8 fixes on tests/sprite_test.py
PEP8 fixes on tests/sei_test.py
PEP8 fixes on tests/sed_test.py
PEP8 fixes on tests/sec_test.py
PEP8 fixes tests/scrolling_test.py
PEP8 fixes on tests/sbc_test.py
PEP8 fixes on tests/rts_test.py
PEP8 fixes on tests/rti_test.py
PEP8 fixes on tests/ror_test.py