fix(aws-ec2): fix capitalization of "VPCEndpointType" to "VpcEndpointType" (#789)

Add a patch to the CFN spec that corrects the capitalization of
the "VpcEndpointType" property of "AWS::EC2::VPCEndpoint".

Fixes #765

Author: Elad Ben-Israel

Diff for: packages/@aws-cdk/cfnspec/spec-source/500_VPCEndpoint_patch.json

@@ -0,0 +1,16 @@
+{
+    "ResourceTypes": {
+        "AWS::EC2::VPCEndpoint": {
+            "patch": {
+                "description": "Rename 'VPCEndpointType' to 'VpcEndpointType': https://github.com/awslabs/aws-cdk/issues/765",
+                "operations": [
+                    {
+                        "from": "/Properties/VPCEndpointType",
+                        "op": "move",
+                        "path": "/Properties/VpcEndpointType"
+                    }
+                ]
+            }
+        }
+    }
+}