Linter: Specify exports in a separate section after all imports.

[zoechi]

For the export

I get

info: Specify exports in a separate section after all imports. (directives_ordering at [datingnode] lib/src/queries_enums.dart:12)

(this warning persists when I fix the part directive to point to a valid part file.

Dart VM version: 1.24.0-dev.6.8 (Mon Jun  5 15:26:29 2017) on "macos_x64"

[pq]

Is this addressed by #679?

[pq]

This should be fixed by https://github.com/dart-lang/linter/pull/679.