docs(readme): update maven dependency version

Author: jzheng2017

README.md

@@ -87,7 +87,7 @@ Latest official release:
 <dependency>
   <groupId>nl.jiankai</groupId>
   <artifactId>spotify-web-api-wrapper</artifactId>
-  <version>1.1.0</version>
+  <version>1.2.0</version>
 </dependency>
 ```