babel-preset-flow@^6.23.0 does not support flow's opaque type aliases

[Gozala]

With the latest release version of babel-cli@6.24.1 & babel-preset-flow@^6.23.0 syntax for Opaque Type Aliases in flow causes parse errors.

Example:

opaque type ID = string;
//     ^ Unexpected token, expected ; (1:7)

[babel-bot]

Hey @Gozala! We really appreciate you taking the time to report an issue. The collaborators
on this project attempt to help as many people as possible, but we're a limited number of volunteers,
so it's possible this won't be addressed swiftly.

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[loganfsmyth]

#5990