Update Scala version and dependent libraries version, and add Travis CI settings.

* Specified sbt version to 0.13.2(current latest version)
* Updated dependent libraries version
* Added Travis CI settings.(using DynamoDBLocal for unit test)
* Set crossScalaVersions 2.10.4, 2.11.0

I have confirmed build success at my repository.
https://travis-ci.org/zaneli/dynamo-scala/builds/24674830