close #64 (coverage reports) and work toward #11 (cross builds)

The `Build.scala` contained far too much crud, this simplifies it a lot. When it comes to making a release, you might want to look into the options for that (`sbt-release` is not the only option).

You are also lucky enough that your code cross compiles between 2.10 and 2.11, so no need to have a separate 2.10 branch! Travis can do the publishing for each.