Update RELEASE.md

Author: domagojkorman

RELEASE.md

@@ -12,4 +12,9 @@ Be sure that [build.gradle](https://github.com/infinum/Android-Goldfinger/blob/m
 
 ### Run gradle task
 
-`./gradlew bintrayUpload`
+`./gradlew clean build javadocs assemble`
+`./gradlew :rx:bintrayUpload :core:bintrayUpload`
+
+### Bintray publish
+
+Manually go to [Bintray page](https://bintray.com/infinum/android), check that all 8 files are there and publish them if everything is OK.