Fix default value for kotlin.Double

Author: nakamura-to

codegen/src/main/java/org/seasar/doma/gradle/codegen/desc/KotlinClassResolver.java

@@ -25,7 +25,7 @@ protected Map<String, LanguageClass> createMap() {
     map.put(Integer.class.getName(), new LanguageClass("Int", "-1"));
     map.put(Long.class.getName(), new LanguageClass("Long", "-1L"));
     map.put(Float.class.getName(), new LanguageClass("Float", "-1f"));
-    map.put(Double.class.getName(), new LanguageClass("Double", "-1"));
+    map.put(Double.class.getName(), new LanguageClass("Double", "-1.0"));
     return map;
   }
 }