Remove references to spdlog in python module

[axsaucedo]

Since we now use the python logger via #118, there is no longer need to have references to spdlog

[alexander-g]

One issue with the python logger I've noticed is that it does not automatically format the strings as spdlog does.
E.g: SPDLOG_DEBUG("{}", 777) will be displayed as "{}" in Python. This should be easily fixable though, because python also allows "{}".format(777)