PP-4627: Upgrade dropwizard from 1.3.5 to 1.3.8

Release notes: https://www.dropwizard.io/1.3.8/docs/about/release-notes.html

1.3.6 fixes a DoS issue in Jackson:
      FasterXML/jackson-databind#2141

1.3.7 fixes incorrect reading of somaxconn on Linux:
      dropwizard/dropwizard#2430

1.3.8 upgrades Guava to fix a DoS (CVE-2018-10237)

pom.xml

@@ -6,7 +6,7 @@
     <artifactId>pay-connector</artifactId>
     <properties>
         <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
-        <dropwizard.version>1.3.5</dropwizard.version>
+        <dropwizard.version>1.3.8</dropwizard.version>
         <wiremock.version>2.20.0</wiremock.version>
         <eclipselink.version>2.7.3</eclipselink.version>
         <guice.version>4.1.0</guice.version>