feat(retrofit): add accessor to exception response body as a map

kork-retrofit/src/main/java/com/netflix/spinnaker/kork/retrofit/exceptions/SpinnakerHttpException.java

@@ -21,7 +21,8 @@
 import com.fasterxml.jackson.annotation.JsonProperty;
 import com.google.common.base.Preconditions;
 import com.netflix.spinnaker.kork.annotations.NonnullByDefault;
-import java.util.Optional;
+import java.util.HashMap;
+import java.util.Map;
 import lombok.Getter;
 import org.springframework.http.HttpHeaders;
 import retrofit.RetrofitError;
@@ -50,20 +51,19 @@ public SpinnakerHttpException(RetrofitError e) {
     super(e);
     this.response = e.getResponse();
     this.retrofit2Response = null;
-    RetrofitErrorResponseBody body =
-        (RetrofitErrorResponseBody) e.getBodyAs(RetrofitErrorResponseBody.class);
+    Map<String, Object> body = getResponseBody(e);
+
     this.rawMessage =
-        Optional.ofNullable(body).map(RetrofitErrorResponseBody::getMessage).orElse(e.getMessage());
+        body != null ? (String) body.getOrDefault("message", e.getMessage()) : e.getMessage();
   }
 
   public SpinnakerHttpException(RetrofitException e) {
     super(e);
     this.response = null;
     this.retrofit2Response = e.getResponse();
-    RetrofitErrorResponseBody body =
-        (RetrofitErrorResponseBody) e.getErrorBodyAs(RetrofitErrorResponseBody.class);
+    Map<String, Object> body = getResponseBody(e);
     this.rawMessage =
-        Optional.ofNullable(body).map(RetrofitErrorResponseBody::getMessage).orElse(e.getMessage());
+        body != null ? (String) body.getOrDefault("message", e.getMessage()) : e.getMessage();
   }
 
   private final String getRawMessage() {
@@ -166,4 +166,12 @@ private static final class RetrofitErrorResponseBody {
       this.message = message;
     }
   }
+
+  public Map<String, Object> getResponseBody(RuntimeException e) {
+    if (this.response != null) {
+      return (Map<String, Object>) ((RetrofitError) e).getBodyAs(HashMap.class);
+    } else {
+      return (Map<String, Object>) ((RetrofitException) e).getErrorBodyAs(HashMap.class);
+    }
+  }
 }