[SYCL] Add build-bot and test support

[agozillon]

Add build-bot and test support to the repository for Intel devices/tests to make sure pull requests are not breaking existing functionality. There should already be some functionality added for this that Intel added and use at the moment: https://github.com/triSYCL/sycl/tree/sycl/unified/master/buildbot

It would be nice to have FPGA compilation support for the build-bot tests, but it does not seem to be feasible as the compilation takes too long and the SDAccel package isn't an Ubuntu package (also the size of it would probably kill the Travis environment).