Calculate Average Steps over last 14 days.

- Show average steps in the index view.
- Calculate average steps while building the data array.
Pass all data in extra_stats hash to Redis via key/value.

- Use length of data to determine average instead of being static.
Add validation checks for access_token and app_id.

- Refactor current methods to accept access_token/app_id.
- Add new method to handle validation.
Refactor strings in global constants.
Add all-time statistics to view.

- Update Rakefile to track the high/low of steps.
- Get all-time stats from redis and pass to index view.
- Modify styling to put last 14 days on left and all-time on the right.
Add exception handling if unable to connect to redis.

- Create new method to call and handle creating the redis connection.
- Do not try to set data if unable to connect to redis.
Partial refactor of Rakefile.

- The initial version was poorly structured.
- Move common functionality into separate methods.
- Rename build_chart_data to build_steps_data and allow it to handle the majority of the work.
Store the high/low steps date separately.

- Store the values and date separately to allow more control.
- Change the text to be built on the index view.
- Retrieve new values and pass to index view.
Store the all time high/low steps date.

- Store the high/low steps date with the high/low steps.
- Defer the date formatting for the Chart labels.
- Include new high/low dates on the index view.
Make styling adjustments to better fit content.

- Add footer section with link to homepage.
- Remove margin/padding from h1..h6 tags.
- Reduce width of statistics element.
- Remove margin/padding from p element in statistics namespace.
- Add clear property to ensure floats are handled properly.