Add artifact migration for sbt-native-packager

[fthomas]

See sbt/sbt-native-packager#1419

Old artifacts: https://scala.jfrog.io/ui/native/sbt-plugin-releases/com.typesafe.sbt/sbt-native-packager/scala_2.12/sbt_1.0
New artifacts: https://repo1.maven.org/maven2/com/github/sbt/sbt-native-packager_2.12_1.0/

/cc @muuki88

[codecov]

Codecov Report

Merging #2263 (35dd804) into master (2fc7153) will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff           @@
##           master    #2263   +/-   ##
=======================================
  Coverage   77.91%   77.91%           
=======================================
  Files         135      135           
  Lines        2291     2291           
  Branches       60       60           
=======================================
  Hits         1785     1785           
  Misses        506      506           

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