Factor out print into separate subcommand
Stub out new 'history' subcommand
Keep track of players past ratings
Use proper type for date
Support printing rating history
Output CSV history
Add command line option for history format
Stub out gnuplot printer
Fill out gnuplot implementation
Plot graph as part of travis job
Update README with new man page
Bump version to 0.2
Update README with info on live page
Merge pull request #44 from simonjbeaumont/rating-history

Rating history