chore(semantic-release): Adds Semantic Release for automatic releasing.

Author: ryasmi

.travis.yml

@@ -1,8 +1,16 @@
 language: node_js
 node_js: node
 sudo: false
+
+before_script:
+  - npm prune
+
 script:
   - npm run build
   - npm run cover
   - npm run lint
   - npm run duplication -- --limit=0.01
+
+after_success:
+  - npm prune --production
+  - npm run semantic-release