Add Node versions 13 and 14 on Travis

Author: jcoglan

.travis.yml

@@ -14,6 +14,8 @@ node_js:
   - "10"
   - "11"
   - "12"
+  - "13"
+  - "14"
 
 before_install:
-  - '[ "${TRAVIS_NODE_VERSION}" = "0.8" ] && npm install -g npm@~1.4.0 || true'
+  - '[ "${TRAVIS_NODE_VERSION}" != "0.8" ] || npm install -g npm@~1.4.0'