Use aws-java-sdk-s3 instead of aws-java-sdk

S3Proxy only needs the former for tests.

pom.xml

@@ -245,7 +245,7 @@
   <dependencies>
     <dependency>
       <groupId>com.amazonaws</groupId>
-      <artifactId>aws-java-sdk</artifactId>
+      <artifactId>aws-java-sdk-s3</artifactId>
       <version>1.9.22</version>
       <scope>test</scope>
     </dependency>