Remove Tasks, and ThreadPoolExecutor. Just enqueue the network calls in Volley, and let it play with them.
Use a ThreadPoolExecutor to parse network responses and update the UI
Use a task to handle network errors
Remove unused tasks
Update comments
Fix an issue where country views doesn't correctly show today/yesterday.
Merge pull request #1217 from wordpress-mobile/feature/1199-Remove-ThreadPoolExecutor-Stats

Stats - Remove ThreadPoolExecutor and use Volley threading capabilities