Loads configurations from env and root.
Use TypesafeConfigReader in SkinnyMailerConfigBase.
Use TypesafeConfigReader in DBSettings and DBMigration
Add comment to SkinnyDBsWithEnv.config
Merge pull request #157 from namutaka/defalut-config

Application configurations load from defaults
Set any object to session in integration test
Merge pull request #159 from namutaka/feature/integration_set_session

Set any objects to session in integration test
Fixed #158 SkinnySessionFilter#skinnySession become infinite loop