Bumping version to 5.3.0 for release (#61)

* Bumping version to 5.3.0 for release, updated README.md to reference latest version

Author: jhalexand

README.md

@@ -23,12 +23,12 @@ Maven:
 <dependency>
     <groupId>com.oracle.labs.olcut</groupId>
     <artifactId>olcut-core</artifactId>
-    <version>5.2.1</version>
+    <version>5.3.0</version>
 </dependency>
 ```
 or from Gradle:
 ```groovy
-implementation 'com.oracle.labs.olcut:olcut-core:5.2.1'
+implementation 'com.oracle.labs.olcut:olcut-core:5.3.0'
 ```
 
 The `olcut-extras` artifact is designed as a small tool for developers, as such you should compile the appropriate 

pom.xml

@@ -35,7 +35,7 @@
     <version>${revision}</version>
     <packaging>pom</packaging>
     <properties>
-        <revision>5.3.0-SNAPSHOT</revision>
+        <revision>5.3.0</revision>
         <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
         <maven.compiler.source>1.8</maven.compiler.source>
         <maven.compiler.target>1.8</maven.compiler.target>