chore: configure npm semantic-release

Author: developher-net

.travis.yml

@@ -1,6 +1,15 @@
 language: node_js
-node_js: 
+node_js:
   - "stable"
-cache:
-  directories:
-    - "node_modules"
+jobs:
+  include:
+    # Define the release stage that runs semantic-release
+    - stage: release
+      node_js: lts/*
+      # Advanced: optionally overwrite your default `script` step to skip the tests
+      # script: skip
+      deploy:
+        provider: script
+        skip_cleanup: true
+        script:
+          - npx semantic-release

README.md

@@ -0,0 +1,2 @@
+[![semantic-release](https://img.shields.io/badge/%20%20%F0%9F%93%A6%F0%9F%9A%80-semantic--release-e10079.svg)](https://github.com/semantic-release/semantic-release)
+[![Build Status](https://travis-ci.org/amclin/advent-of-code.svg?branch=master)](https://travis-ci.org/amclin/advent-of-code)