Fix travis CI build for S4

With gradle 2.1, running the `gradle wrapper` tool in the S4 base directory does not work
due to a missing parameter in the s4 build.gradle file.
Travis CI runs gradle 2.1 by default from september 2014. As a result, the S4 build fails.

This patch is a workaround that includes the gradle 1.4 dependencies in the samoa repo and
copies them appropriately during the travis CI build.
this directory seems to exist already, probably this line is not needed