fixed rum rates to update within port and ship update functions
Merge branch 'master' of https://github.com/fenaren/cs420-game into rumrate

Merged with master.
fixed time to convert to seconds
Merge branch 'rumrate' of https://github.com/fenaren/cs420-game into rumrate
limited rum by max and min
Changed most ports to buy ports, 3 remaining sel ports.  Rum rates at ports (and ship) still need to be updated.
changed delta_t to seconds for comparison
Fixed rum rate calculation.
Fixed Port rum change calculation, corrected Ship.
Merge pull request #39 from fenaren/rumrate

Rumrate
Merge remote-tracking branch 'origin/master' into balancing