Use StringUtilities.normalize to allow compilation with SBT 0.12.

[fiadliel]

Project.normalizeModuleID is recommended for use with SBT 0.13, but it
doesn't exist with 0.12. This uses the deprecated call instead.

[muuki88]

This looks okay to me, but I'm not sure if we need it. See my last comment

[fiadliel]

I was trying to cross-build against scala 2.9/sbt 0.12, with sbt +publishLocal

[info] Set current project to sbt-native-packager (in build file:/Users/gcoady/docker/sbt-native-packager/upstream/sbt-native-packager/)
[info] Setting version to 2.9.2
[info] Set current project to sbt-native-packager (in build file:/Users/gcoady/docker/sbt-native-packager/upstream/sbt-native-packager/)

[error] /Users/xxx/git/sbt-native-packager/src/main/scala/com/typesafe/sbt/packager/docker/DockerPlugin.scala:161: value normalizeModuleID is not a member of object sbt.Project
[error]       normalizedName <<= name apply Project.normalizeModuleID,
[error]                                             ^

And it looks like the plugin is still published for SBT 0.12: https://bintray.com/sbt/sbt-plugin-releases/sbt-native-packager/0.7.1/view/files/com.typesafe.sbt/sbt-native-packager/scala_2.9.2/sbt_0.12

[fiadliel]

Though perhaps you meant that you will implement packageName before the next release, so this code will be removed? Anyway, this fixes the current compilation failure on master.

[muuki88]

Yeah. You're right, even we change this later this will fix the issue temporary.

[fiadliel]

Thanks!