Update breaking changes and java requirements

Fixes elastic#6178

Author: suyograo

docs/static/breaking-changes.asciidoc

@@ -221,6 +221,13 @@ If you have manually specified `sincedb_path` as part of the configuration, this
 If you are moving from Logstash 2.x to Logstash 5.0, and you would like to use the existing SinceDB file,
 then it must be copied over to `path.data` manually to use the save state (or the path needs to be changed to point to it).
 
+[float]
+==== GeoIP Filter
+
+The GeoIP filter has been updated to use MaxMind's GeoIP2 database. Previous GeoIP version is now considered legacy 
+by MaxMind. As a result of this, `.dat` version files are no longer supported, and only `.mmdb` format is supported. 
+The new database will not include ASN data in the basic free database file.
+
 [float]
 === Ruby Filter and Custom Plugin Developers
 

docs/static/getting-started-with-logstash.asciidoc

@@ -15,7 +15,7 @@ This section includes the following topics:
 [[installing-logstash]]
 === Installing Logstash
 
-NOTE: Logstash requires Java 8 or later. Use the
+NOTE: Logstash requires Java 8. Java 9 is not supported. Use the
 http://www.oracle.com/technetwork/java/javase/downloads/index.html[official Oracle distribution] or an open-source
 distribution such as http://openjdk.java.net/[OpenJDK].