[Release 0.5.8] Updates next and latest version (#192)

* [Release 0.5.8] Update latest version in README.adoc to 0.5.8

* [Release 0.5.8] Update next snapshot version to 0.5.9-SNAPSHOT

Author: onobc

README.adoc

@@ -19,7 +19,7 @@
 = Reactive client for Apache Pulsar
 
 :github: https://github.com/apache/pulsar-client-reactive
-:latest_version: 0.5.7
+:latest_version: 0.5.8
 
 Reactive client for Apache Pulsar which is compatible with the Reactive Streams specification.
 This uses Project Reactor as the Reactive Streams implementation.

gradle.properties

@@ -17,4 +17,4 @@
 # under the License.
 #
 
-version=0.5.8
+version=0.5.9-SNAPSHOT