postline 0.3.1

Same code as 0.3.0, republished under the maintainer's public address. 0.3.0 and
earlier npm versions recorded a private email in their publish metadata and are
withdrawn. Projects pinned to 0.3.0 should move to 0.3.1 (POSTLINE_VERSION and
uses: 1cbyc/postline@v0.3.1 in the workflow).

For everything in the 0.3 line (preview, pull request previews, doctor, alerts) see the 0.3.0 notes.

Install: npm install --global postline@0.3.1