Use "POST" For Options Http Method When Defining It In AWS SAML

Man oh man, this is something that tripped me up when moving a bunch of lambda functions over to a different region. After lots and lots of tweaks, googles, and let's-try-its I've landed upon a nice AWS CodePipeline template that I like to use for new lambda functions. Here it is below in all of its glory!

---

AWSTemplateFormatVersion: 2010-09-09
Transform:
- AWS::Serverless-2016-10-31

Parameters:
  ProjectId:
    Type: String
    Description: Lambda Function with API Gateway.
  Environment:
      Type: String
      Description: the environment...

# Enable blue/green deployments using this Globals section. For instructions, see the AWS CodeStar User Guide:
# https://docs.aws.amazon.com/codestar/latest/userguide/how-to-modify-serverless-project.html?icmpid=docs_acs_rm_tr
#
# Globals:
#   Function:
#     AutoPublishAlias: live
#     DeploymentPreference:
#       Enabled: true
#       Type: Canary10Percent5Minutes

Resources:
  Lambda:
    Type: AWS::Serverless::Function
    Properties:
      FunctionName: !Join ['-', [!Ref 'ProjectId', !Ref 'Environment']]
      Role: arn:aws:iam::23452345345:role/My-Worker-Lambda      
      Handler: index.handler
      Runtime: nodejs8.10
      Timeout: 120
      Environment:
        Variables:
          NODE_ENV: production
          db_connection: mongodb://WriteSvcUser:sdfgsdfgsdfgsdfg@prd-cul-mongoclient-234523453.us-east-1.elb.amazonaws.com/myDb
      
  RestApi:
    Type: AWS::Serverless::Api
    Properties:
      StageName: !Ref 'Environment'
      DefinitionBody:
        swagger: "2.0"
        info:
          version: "1.0"
          title: !Join ['-', [!Ref 'ProjectId', !Ref 'Environment']]
        host: "i4r9f0ntaf.execute-api.us-east-1.amazonaws.com"
        basePath: !Join ['', ['/', !Ref 'Environment']]
        schemes:
        - "https"
        paths:
          /:
            post:
              responses:
                "200":
                  description: "200 response"
              x-amazon-apigateway-integration:
                credentials: 'arn:aws:iam::234524352345:role/My-Worker-Lambda'
                uri: !Join ['', ['arn:aws:apigateway:us-east-1:lambda:path/2015-03-31/functions/arn:aws:lambda:us-east-1:234523466554:function:', !Ref 'ProjectId', '/invocations']]
                passthroughBehavior: "when_no_match"
                httpMethod: "POST"
                type: "aws_proxy"
            options:
              responses:
                "200":
                  description: "200 response"
              x-amazon-apigateway-integration:
                credentials: 'arn:aws:iam::133345006009:role/My-Worker-Lambda'
                uri: !Join ['', ['arn:aws:apigateway:us-east-1:lambda:path/2015-03-31/functions/arn:aws:lambda:us-east-1:133345006009:function:', !Ref 'ProjectId', '/invocations']]
                passthroughBehavior: "when_no_match"
                httpMethod: "POST"
                type: "aws_proxy"

Notice how in the second-to-last line here it says, "httpMethod: "POST"" even though that is describing the OPTIONS http event. Now you DO NOT want to put "OPTIONS" as the value in here or things will go badly! Now, go forth and leverage these awesome AWS services to do incredible things!