feat(ci): improve continuous integration

Continuous integration improvements
- Travis builds no longer run on non-master branch pushes
- TravisBuddy integration
- Unit tests (code correctness) and validation checks (everything else) run in parallel
- add semantic-release to automate publishing once PRs merge
- add commitlint as part of travis build

.commitlintrc.json

@@ -0,0 +1,3 @@
+{
+    "extends": ["@commitlint/config-angular"]
+}

.releaserc

@@ -0,0 +1,27 @@
+{
+  "branch": master",
+  "tagFormat": "v${version}",
+  "verifyConditions": [
+    "@semantic-release/npm",
+    {
+      "path": "@semantic-release/github",
+      "assets": {
+        "path": "dist/*"
+      }
+    }
+  ],
+  "analyzeCommits": "@semantic-release/commit-analyzer",
+  "generateNotes": "@semantic-release/release-notes-generator",
+  "prepare": "@semantic-release/npm",
+  "publish": [
+    "@semantic-release/npm",
+    {
+      "path": "@semantic-release/github",
+      "assets": {
+        "path": "dist/*"
+      }
+    }
+  ],
+  "success": [],
+  "fail": []
+}

.travis.yml

@@ -1,17 +1,36 @@
 language: node_js
-
 node_js:
   - 8.9.4
 
+branches:
+  only:
+    - master
+    - /v\d+\.\d+\.d+$/
+
 cache:
-  directory:
-    - studio-frontend/node_modules/
+  directories:
+    - "node_modules"
 
-script:
-  - make package-lock.validate
-  - make i18n.pre_validate
-  - npm run lint
-  - npm run test
+stages:
+  - PR checks ✅
+  - name: Ship It 🚢
+    if: env(TRAVIS_BRANCH) = master
+jobs:
+  include:
+    - stage: PR checks ✅
+      env:
+        - NAME=Unit Tests
+      script: npm run test
+      after_script:
+        - codecov
+    - stage: PR checks ✅
+      env:
+        - NAME=Validation Checks
+      script: ./.travis/validate_changes_for_merge.sh
+    - stage: Ship It 🚢
+      env:
+        - NAME=Publish
+      script: rm -rf dist/ && rm -rf node_modules/ && npm install && npm run build && semantic-release
 
-after_script:
-  - codecov
+notifications:
+  webhooks: https://www.travisbuddy.com/

.travis/validate_changes_for_merge.sh

@@ -0,0 +1,10 @@
+#!/bin/bash
+
+# This script exists so that all validation checks can be run in parallel with a single compound exit status
+
+EXIT_STATUS=0
+npm run lint || EXIT_STATUS=$?
+make package-lock.validate || EXIT_STATUS=$?
+make i18n.pre_validate || EXIT_STATUS=$?
+commitlint-travis || EXIT_STATUS=$?
+exit $EXIT_STATUS