Add Redis dependency and configuration for Steps webapp.

- Add redis gem dependency to Gemfile.
- Configure the redis server settings in config.ru.
Retrieve initial values from Redis and pass to index view.

- Get last_updated and steps_data values.
- Temporarily display them in index for testing.
Use the @steps variable for the chart.js data.
Add Rakefile to handle setting the stats in Redis.

- Add rake dependency to Gemfile.
- Create template rake file with dummy data for now.
Build Chart Data using Ruby and convert to JSON.

- Remove commented out javascript example.
Pull steps data from Nike Plus API.

- Add method in Rakefile to get the data from NikePlus given Access Token and return a modified version of the results.
- Update build_chart_data to use the data from the API call.
Handle dates better when building data.

- Use simpler format for the Date labels on the chart.
- Use a friendlier format for the Last Updated date being set.