adding snapshot support (#316)

Author: ammokhov

src/main/java/software/amazon/cloudformation/AbstractWrapper.java

@@ -261,6 +261,7 @@ public void processRequest(final InputStream inputStream, final OutputStream out
         if (resourceHandlerRequest != null) {
             resourceHandlerRequest.setPreviousResourceTags(getPreviousResourceTags(request));
             resourceHandlerRequest.setStackId(getStackId(request));
+            resourceHandlerRequest.setSnapshotRequested(request.getSnapshotRequested());
         }
 
         this.metricsPublisherProxy.publishInvocationMetric(Instant.now(), request.getAction());

src/main/java/software/amazon/cloudformation/proxy/HandlerRequest.java

@@ -34,5 +34,6 @@ public class HandlerRequest<ResourceT, CallbackT> {
     private RequestData<ResourceT> requestData;
     private String stackId;
     private CallbackT callbackContext;
+    private Boolean snapshotRequested;
     private RequestContext<CallbackT> requestContext;
 }

src/main/java/software/amazon/cloudformation/proxy/ResourceHandlerRequest.java

@@ -42,6 +42,7 @@ public class ResourceHandlerRequest<T> {
     private String awsPartition;
     private String logicalResourceIdentifier;
     private String nextToken;
+    private Boolean snapshotRequested;
     private String region;
     private String stackId;
 }

src/test/java/software/amazon/cloudformation/proxy/handler/ServiceHandlerWrapper.java

@@ -82,7 +82,7 @@ protected ResourceHandlerRequest<Model> transform(final HandlerRequest<Model, St
         return ResourceHandlerRequest.<Model>builder().desiredResourceState(desiredResourceState)
             .previousResourceState(previousResourceState).desiredResourceTags(getDesiredResourceTags(request))
             .systemTags(systemTags).logicalResourceIdentifier(request.getRequestData().getLogicalResourceId())
-            .nextToken(request.getNextToken()).build();
+            .nextToken(request.getNextToken()).snapshotRequested(request.getSnapshotRequested()).build();
     }
 
     @Override