Event-info for SNS fails to find events due to case differences.

[XerTheSquirrel]

Description

SNS events are not recorded by the Python plugin due to case differences.

Steps to reproduce the issue:

1. Setup an AWS Lambda for Python, using standard IOpipe with the standard plugin inclusions.
2. Use the following SNS sample:

{
  "Records": [
    {
      "EventVersion": "1.0",
      "EventSubscriptionArn": "arn:aws:sns:EXAMPLE",
      "EventSource": "aws:sns",
      "Sns": {
        "SignatureVersion": "1",
        "Timestamp": "1970-01-01T00:00:00.000Z",
        "Signature": "EXAMPLE",
        "SigningCertUrl": "EXAMPLE",
        "MessageId": "95df01b4-ee98-5cb9-9903-4c221d41eb5e",
        "Message": "Hello from SNS!",
        "MessageAttributes": {
          "Test": {
            "Type": "String",
            "Value": "TestString"
          },
          "TestBinary": {
            "Type": "Binary",
            "Value": "TestBinary"
          }
        },
        "Type": "Notification",
        "UnsubscribeUrl": "EXAMPLE",
        "TopicArn": "arn:aws:sns:EXAMPLE",
        "Subject": "TestInvoke"
      }
    }
  ]
}

3. Execute the lambda, it does not matter what it does.

Describe the results you received:

SNS events do not appear in the dashboard.

Describe the results you expected:

Expected SNS events to be on the Dashboard.

Additional information you deem important (e.g. issue happens only occasionally):

I propose that comparing the keys without regards to case for events will fix the issue.

Modifying the keys to match the exact casing in the SNS sample event, event-info works. Since the previous keys and other keys might be case insensitive (I have run into this with the Java agent), I would suggest the comparison be case insensitive.