Merge pull request #183 from awslabs/dependabot/maven/aws-java-sdk.version-2.20.15

Bump aws-java-sdk.version from 2.19.13 to 2.20.15

Author: ziyanli-amazon

pom.xml

@@ -30,7 +30,7 @@
         </developer>
     </developers>
     <properties>
-        <aws-java-sdk.version>2.19.13</aws-java-sdk.version>
+        <aws-java-sdk.version>2.20.15</aws-java-sdk.version>
         <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
     </properties>