Add configure file used yaml

[cnsworder]

Add configure file used yaml

• default used ~/.config/.classify.conf file;
• -c or --config set a config file;

[bhrigu123]

Hey, this is great. Just a few things:

• Could you handle the exception when the config file given as input has wrong syntax (like missing bracket, comma, etc.), and exit the program? It throws yaml.parser.ParserError.
• Also, I think it would be great to rename the classify part of the default config file to classifier.
• And, one question: What was the need to remove check isFile in d99efc8?

Thanks.