Disable parallel execution of tests in spray.

This is a workaround for non-deterministic failures we've observed. See
https://github.com/scala/community-builds/pull/69#issuecomment-63324597
for details.
Merge pull request #74 from gkossakowski/spray-disable-parrallel-tests

Disable parallel execution of tests in spray.
Adding Scala Records to the build.