message: Export NPM_VERSION variable in Makefile
  Change-type: patch
  Changelog-entry: Export NPM_VERSION variable in Makefile
diff: # ---------------------------------------------------------------------
  RESIN_SCRIPTS ?= ./scripts/resin
  -NPM_VERSION ?= 6.7.0
  +export NPM_VERSION ?= 6.7.0
  S3_BUCKET = artifacts.ci.balena-cloud.com
  # This directory will be completely deleted by the `clean` rule
  