Bump to Scala 2.13.0 (#28)

Merge pull request #27 from gitbucket-plugins/plugin-registry

Bump to sbt-gitbucket-plugin 1.3.0 to be hosted by the plugin registry

update docs

fix Controller mapping

Compile against GitBucket 4.16.o

release 1.4.0

release 1.3.0

release 1.2.0 compatibility with gitbucket 4.x