v0.4.0 added logger

Added spdlog for logging (https://github.com/gabime/spdlog)

In python to access the logging settings (default update_loggers(False, "thermofun.log", 2) )

import thermofun as fun
# True for logging to output instead of file,
# file name, 2 is the logging level for info, warn, error, and critical messages.
fun.update_loggers(False, "thermofun.log", 2)
# clears the log file
fun.clear_loggers("thermofun.log")