Throw exception when permissions are not provided for connectors (#260)

Author: xazhao

tests/translator/input/error_connector.yaml

@@ -155,3 +155,20 @@ Resources:
         Arn:
       Permissions:
         - Write
+
+  NoPermissionConnector:
+    Type: AWS::Serverless::Connector
+    Properties:
+      Source:
+        Id: MyFunction
+      Destination:
+        Id: MyQueue
+
+  EmptyPermissionConnector:
+    Type: AWS::Serverless::Connector
+    Properties:
+      Source:
+        Id: MyFunction
+      Destination:
+        Id: MyQueue
+      Permission:

tests/translator/output/error_connector.json

@@ -38,7 +38,13 @@
       },
       {
         "errorMessage": "Resource with id [BothIdAndOtherProps] is invalid. Must provide either 'Id' or a combination of the other properties, not both."
+      },
+      {
+        "errorMessage": "Resource with id [NoPermissionConnector] is invalid. Missing required property 'Permissions'"
+      },
+      {
+        "errorMessage": "Resource with id [EmptyPermissionConnector] is invalid. property Permission not defined for resource of type AWS::Serverless::Connector"
       }
     ], 
-    "errorMessage": "Invalid Serverless Application Specification document. Number of errors found: 13. Resource with id [BothIdAndOtherProps] is invalid. Must provide either 'Id' or a combination of the other properties, not both. Resource with id [MissingLambdaFunctionArn] is invalid. Source.Arn is missing. Resource with id [MissingRole] is invalid. Unable to get IAM role name from 'Source' resource. Resource with id [MissingRoleDestination] is invalid. Unable to get IAM role name from 'Destination' resource. Resource with id [MissingSnsTopicArn] is invalid. Destination.Arn is missing. Resource with id [MissingSqsQueueUrl] is invalid. Destination.Arn is missing. Resource with id [NoIdMissingType] is invalid. 'Type' is missing or not a string. Resource with id [NonExistentLogicalId] is invalid. Unable to find resource with logical ID 'ThisDoesntExist'. Resource with id [NonStrId] is invalid. 'Id' is missing or not a string. Resource with id [ResourceWithoutType] is invalid. 'Type' is missing or not a string. Resource with id [UnsupportedAccessCategory] is invalid. Unsupported 'Permissions' provided; valid values are: Read, Write. Resource with id [UnsupportedAccessCategoryCombination] is invalid. Unsupported 'Permissions' provided; valid combinations are: Read + Write. Resource with id [UnsupportedType] is invalid. Unable to create connector from AWS::Fancy::CoolType to AWS::Lambda::Function; it's not supported or the template is invalid."
+    "errorMessage": "Invalid Serverless Application Specification document. Number of errors found: 15. Resource with id [BothIdAndOtherProps] is invalid. Must provide either 'Id' or a combination of the other properties, not both. Resource with id [EmptyPermissionConnector] is invalid. property Permission not defined for resource of type AWS::Serverless::Connector Resource with id [MissingLambdaFunctionArn] is invalid. Source.Arn is missing. Resource with id [MissingRole] is invalid. Unable to get IAM role name from 'Source' resource. Resource with id [MissingRoleDestination] is invalid. Unable to get IAM role name from 'Destination' resource. Resource with id [MissingSnsTopicArn] is invalid. Destination.Arn is missing. Resource with id [MissingSqsQueueUrl] is invalid. Destination.Arn is missing. Resource with id [NoIdMissingType] is invalid. 'Type' is missing or not a string. Resource with id [NoPermissionConnector] is invalid. Missing required property 'Permissions'. Resource with id [NonExistentLogicalId] is invalid. Unable to find resource with logical ID 'ThisDoesntExist'. Resource with id [NonStrId] is invalid. 'Id' is missing or not a string. Resource with id [ResourceWithoutType] is invalid. 'Type' is missing or not a string. Resource with id [UnsupportedAccessCategory] is invalid. Unsupported 'Permissions' provided; valid values are: Read, Write. Resource with id [UnsupportedAccessCategoryCombination] is invalid. Unsupported 'Permissions' provided; valid combinations are: Read + Write. Resource with id [UnsupportedType] is invalid. Unable to create connector from AWS::Fancy::CoolType to AWS::Lambda::Function; it's not supported or the template is invalid."
   }