Update java (#51)

Author: Denis-Averin

codegen/Templates/java/pom.mustache

@@ -253,14 +253,14 @@
         <maven.compiler.source>${java.version}</maven.compiler.source>
         <maven.compiler.target>${java.version}</maven.compiler.target>
         <gson-fire-version>1.8.5</gson-fire-version>
-        <swagger-core-version>1.6.4</swagger-core-version>
+        <swagger-core-version>1.6.6</swagger-core-version>
         <okhttp-version>2.7.5</okhttp-version>
-        <gson-version>2.8.9</gson-version>
+        <gson-version>2.9.0</gson-version>
         {{#joda}}
             <jodatime-version>2.9.9</jodatime-version>
         {{/joda}}
         {{#threetenbp}}
-        <threetenbp-version>1.5.1</threetenbp-version>
+        <threetenbp-version>1.6.0</threetenbp-version>
         {{/threetenbp}}
         <maven-plugin-version>1.0.0</maven-plugin-version>
         <junit-version>4.13.2</junit-version>