specify version for error_prone_annotations dependency

Author: SirCotare

pom.xml

@@ -64,6 +64,7 @@
         <dependency>
             <groupId>com.google.errorprone</groupId>
             <artifactId>error_prone_annotations</artifactId>
+            <version>${errorprone.version}</version>
         </dependency>
 
         <!-- Testing -->