Move tokens.yml to a valid_scorecards directory

Signed-off-by: Sam Phippen <samphippen@googlemail.com>
Add an invalid scorecard from #1

Signed-off-by: Sam Phippen <samphippen@googlemail.com>
Make it load a file from the command line args

Signed-off-by: Sam Phippen <samphippen@googlemail.com>
Make it shout when you score an invalid card

Closes #1

Signed-off-by: Sam Phippen <samphippen@googlemail.com>
Add a test script

Signed-off-by: Sam Phippen <samphippen@googlemail.com>
whitespace
Update readme to mention token name argument.

Also explain better what the tokens files contain.