Added a deployment job to publish tagged releases to npm

.travis.yml

@@ -3,6 +3,7 @@
 # https://docs.travis-ci.com/user/customizing-the-build/
 # https://docs.travis-ci.com/user/migrating-from-legacy/
 
+filter_secrets: false
 language: node_js
 
 node_js:
@@ -20,3 +21,18 @@ script: npm run lint && npm run coverage
 after_success:
   # send code-coverage data to Coveralls
   - cat ./coverage/lcov.info | coveralls
+
+jobs:
+  include:
+    - stage: Deploy
+      name: Publish to npm
+      script: true
+      after_success: true
+      deploy:
+        provider: npm
+        email: $NPM_EMAIL
+        api_key: $NPM_API_KEY
+        skip_cleanup: true
+        on:
+          tags: true
+          branch: master

package.json

@@ -29,7 +29,7 @@
     "coverage": "nyc --reporter=text --reporter=lcov mocha",
     "upgrade": "npm-check -u",
     "bump": "bump --prompt --tag --push --all",
-    "release": "npm run upgrade && npm run test && npm run bump && npm publish"
+    "release": "npm run upgrade && npm run test && npm run bump"
   },
   "devDependencies": {
     "browserify": "^16.2.3",