add automatic release (#31)

Author: jdelbick

.releaserc.json

@@ -0,0 +1,35 @@
+{
+    "plugins": [
+      ["@semantic-release/commit-analyzer", {
+        "preset": "eslint",
+        "releaseRules": [
+        {
+          "subject": "*",
+          "release": false
+        },
+        {
+          "subject": "BREAKING-RELEASE:*",
+          "release": "major"
+        },
+        {
+          "subject": "FEATURE-RELEASE:*",
+          "release": "minor"
+        },
+        {
+          "subject": "BUGFIX-RELEASE:*",
+          "release": "patch"
+        }
+        ]
+      }],
+      ["@semantic-release/release-notes-generator", {
+        "preset": "eslint"
+      }],
+      ["@semantic-release/npm"],
+      ["@semantic-release/git", {
+        "preset": "eslint",
+        "assets": ["package.json", "package-lock.json"],
+        "message": " [ci skip] no-release: version number update"
+      }],
+      ["@semantic-release/github"]
+    ]
+}

.travis.yml

@@ -25,8 +25,23 @@ install:
   - npm version
   - npm install
 
-script:
-  - npm test
+jobs:
+  include:
+    - stage: Test
+      script: npm test
+    - stage: release
+      if: branch = master
+      node_js: "12"
+      script: skip
+      before_deploy:
+        - "echo 'semantic release...'"
+      deploy:
+        on:
+          branch: master
+          condition:  $TRAVIS_OS_NAME == linux
+        provider: script
+        skip_cleanup: true
+        script: npx semantic-release --debug
 
 after_success:
   - npm run report-coverage