Add flyway postgres maven module needed by flyway 10.17.1.

Author: mbjones

pom.xml

@@ -89,6 +89,11 @@
             <artifactId>flyway-maven-plugin</artifactId>
             <version>${flyway.version}</version>
         </dependency>
+        <dependency>
+            <groupId>org.flywaydb</groupId>
+            <artifactId>flyway-database-postgresql</artifactId>
+            <version>10.17.1</version>
+        </dependency>
         <dependency>
             <groupId>org.mockito</groupId>
             <artifactId>mockito-core</artifactId>