message: Update CHANGELOG.md
  Remove duplicate `## Feature Flags` from `CHANGELOG`
diff: The `async` feature flag is deprecated.
  Prefer `{ default-features = false, features = ["full"] }` instead.
  -## Feature Flags
  -In this version, new feature flags have been added t
  -and compile time in downstream applications.
  -
  ## Feature Flags
  By default the `full` stripe api is enabled.
  