Upgrade project to sbt 1.0

[ignasi35]

Bumping the sbt version will allow using newer AkkaHTTp instead of

libraryDependencies += "com.typesafe.akka" % "akka-http-experimental_2.10" % "2.0.4"

[TimMoore]

I took a look at this once, and it's going to be a bit tricky.

We'll need to update all of the plugins to 1.x-compatible versions, but at least sbt-concat has been abandoned without any recent updates, so we'll need to find an alternative. Hopefully there is a simple one, but I asked once on Lightbend Slack and nobody responded. I am pretty much in the dark on sbt-web things... 😦

[dwijnand]

sbt-concat 0.2.0 with sbt 1 support is out:

http://dl.bintray.com/sbt/sbt-plugin-releases/net.ground5hark.sbt/sbt-concat/scala_2.12/sbt_1.0/0.2.0/