Missing DMG and EXE files from assets

[emettely]

Describe the bug
Go to Releases and see the dropdown of assets. Sometimes the EXE or AppImage disappears and DMG is not there either.
The deployment here: https://travis-ci.org/bbc/digital-paper-edit-electron seems to be pretty happy with the whole process, so wondering why it's not pushing it to Git

Expected behavior
Should see 3: DMG and EXE / APPIMAGE in assets.

Screenshots

Additional context
Possibly change to node v 10: see 1.1.1...master