Remove d3 from dependencies.  Usin CDN
Setup new sensor data callbacks
Move graph code into get_sensor_data callback and add CSS
Add spacing and transition to bars
Merge pull request #59 from kyle-rader/use-d3

Use d3
Changed getevents to take a limit instead of a start time
Merge pull request #60 from kyle-rader/use-d3

Changed getevents to take a limit instead of a start time
Add MIT license.