cli.rb patch

[RyanFleck]

Adapted cli.rb so it works on my personal windows and linux environments.

• Infer second argument if only .rule/.table file location is passed.
• Use rule/table parser depending on file extension.
• Throw errors if file-type is incorrect or missing
• Fix travis builds by bumping RVM target
• Allow a directory of .rule/.table files to be passed as first argument