Add get absolute url on image models
fix pep8 on get absilute url image model
./opps/image/models.py:35:31: E225 missing whitespace around operator
./opps/image/models.py:35:66: E225 missing whitespace around operator
./opps/image/models.py:35:66: E712 comparison to True should be 'if cond
is True:' or 'if cond:'