New argument -> config

[Wabri]

Add a new argument for yapi called config, this new argument must give the actual configuration for yapi and ask if some of config value needs to be change. if config is follow by one or more of this "--<field_name>=<field_new_value>" it means that field must change with that value. in this case is not necessary to run the console request previously explained.

examples:

• yapi config --platform=darwin
• yapi config --want_soft_link=True --keep_cache=False
• yapi config --ignore=test.sh,atom.sh,pycharm.sh --installed=atom,pycharm

The last one is give a particular example of list of value, is probably necessary to update this line of yapi.py:
https://github.com/YetAnotherPackageInstaller/YAPI/blob/6ca5410572d9df4ff6e7a8c78cdef1db3ead6eea/yapi.py#L54
or prevent the change of this line by split the value list in argument of config with a space between the comma and the next character.