Release with build stages

Also update to Node 8, and specify the stable 8 for build/lint/release, rather than latest stable Node, so less stuff changes.

.travis.yml

@@ -1,6 +1,6 @@
 language: node_js
 node_js:
-- 6
+- 8
 - node
 env:
   matrix:
@@ -12,26 +12,22 @@ script: npm run $NPM_SCRIPT
 jobs:
   include:
   - env: NPM_SCRIPT=build
-    node_js: node
+    node_js: 8
+    if: not (branch in (master, develop) and type != pull_request)
   - env: NPM_SCRIPT=lint
-    node_js: node
-after_script:
-- |
-  # RELEASE_BRANCHES and NPM_TOKEN defined in Travis settings panel
-  declare exitCode
-  $(npm bin)/travis-after-all
-  exitCode=$?
-  if [[
-    # Execute after all jobs finish successfully
-    $exitCode = 0 &&
-    # Only release on release branches
-    $RELEASE_BRANCHES =~ $TRAVIS_BRANCH &&
-    # Don't release on PR builds
-    $TRAVIS_PULL_REQUEST = "false"
-  ]]; then
-    # Authenticate NPM
-    echo "//registry.npmjs.org/:_authToken=\${NPM_TOKEN}" > .npmrc
-    # Set version to timestamp
-    npm --no-git-tag-version version $($(npm bin)/json -f package.json version)-prerelease.$(date +%s)
-    npm publish
-  fi
+    node_js: 8
+  - stage: release
+    node_js: 8
+    script: skip
+    before_deploy:
+    - npm --no-git-tag-version version 0.1.0-prerelease.$(date +%Y%m%d%H%M%S)
+    deploy:
+    - provider: npm
+      on:
+        all_branches: true
+      email: $NPM_EMAIL
+      api_key: $NPM_TOKEN
+stages:
+- test
+- name: release
+  if: branch in (master, develop) and type != pull_request

package.json

@@ -34,8 +34,6 @@
     "babel-preset-env": "^1.6.1",
     "eslint": "^3.19.0",
     "eslint-config-scratch": "^3.1.0",
-    "json": "^9.0.6",
-    "travis-after-all": "^1.4.4",
     "webpack": "^4.8.0",
     "webpack-cli": "^2.0.15",
     "tap": "^12.0.1"