Merge pull request #423 from akka/raboof-patch-1

Add more details to RELEASING.md

RELEASING.md

@@ -1,8 +1,14 @@
 ## Releasing
 
-1. Create a [new release](https://github.com/akka/alpakka/releases/new) with the next tag version (e.g. `v0.3`), title and release description including notable changes mentioning external contributors.
+1. Create a [new release](https://github.com/akka/alpakka/releases/new) with:
+  * the next tag version (e.g. `v0.3`)
+  * title and release description including notable changes
+  * link to the [milestone](https://github.com/akka/alpakka/milestones) showing an overview of closed issues for this release
+  * overview of contributors generated by `./scripts/authors.scala`
 2. Travis CI will start a [CI build](https://travis-ci.org/akka/alpakka/builds) for the new tag and publish artifacts to Bintray.
-3. Login to [Bintray](https://bintray.com/akka/maven/alpakka) and sync artifacts to Maven Central.
+3. Login to [Bintray](https://bintray.com/akka/maven/alpakka) and sync artifacts to Maven Central:
+  * Go to the 'Maven Central' tab and use your sonatype credentials.
+  * This can take a long time (you can check https://oss.sonatype.org/#stagingRepositories for progress)
 
 ### Releasing only updated docs