ratelimit methods not working as expected

[barrettkingram]

Issue Summary

Response#ratelimit is not working as expected. It just returns nil every time. I believe this is because of a header capitalization mismatch between what that method expects and what is actually returned.

Code Snippet

sendgrid_client = SendGrid::API.new(api_key: SENDGRID_API_KEY).client
data = {automatic_security: true, custom_spf: false, default: false, domain: "my-test-domain.com", subdomain: "abc"}.stringify_keys
response = sendgrid_client.whitelabel.domains.post(request_body: data)

# This returns nil
response.headers["X-RateLimit-Limit"]

# This returns ["1"]
response.headers["x-ratelimit-limit"]

# This returns nil
response.ratelimit

Technical details:

• ruby-http-client version: 3.5.1
• ruby version: 2.5