Fix build to use released scala-continuations artifacts for Scala 2.11

Looks like version 1.0.0 of the scala-continuations-plugin was never
published to Maven Central:

http://search.maven.org/#search%7Cga%7C1%7Corg.scala-lang.plugins

...and note also that the published coordinate for
"scala-continuations-plugin" includes the minor binary version number,
ie "2.11.0", not "2.11".

"org.scala-lang.plugins" % "scala-continuations-plugin_2.11.0" % "1.0.1"

http://search.maven.org/#artifactdetails%7Corg.scala-lang.plugins%7Cscala-continuations-plugin_2.11.0%7C1.0.1%7Cbundle
Merge pull request #28 from rtyley/fix-for-released-scala-2.11-continuations-artifacts

Fix build to use released scala-continuations artifacts for Scala 2.11