App can now download temperature/light data from backend

Signed-off-by: Greg Meiste <greg.meiste@gmail.com>
Fix spelling of AppConstants class

Signed-off-by: Greg Meiste <greg.meiste@gmail.com>
Fix typo in RasPiContract.RasPiReport.CONTENT_URI

Signed-off-by: Greg Meiste <greg.meiste@gmail.com>
Update type of degF column in sqlite database

Signed-off-by: Greg Meiste <greg.meiste@gmail.com>
Enable Objectify caching. Closes #10

Signed-off-by: Greg Meiste <greg.meiste@gmail.com>
Store downloaded records to sqlite database

Signed-off-by: Greg Meiste <greg.meiste@gmail.com>