feat: drop Node.js 0.12 support (#423)

Author: leeyeh

.travis.yml

@@ -2,7 +2,6 @@ language: node_js
 
 node_js:
 - "4"
-- "0.12"
 
 sudo: false
 
@@ -15,7 +14,7 @@ script:
   - npm test && codecov
   - npm run build
 after_success:
-  - if [[ `node -v` == v4* ]] && [[ "$TRAVIS_BRANCH" == "next" ]] && [[ "${TRAVIS_PULL_REQUEST}" = "false" ]]; then
+  - if [[ "$TRAVIS_BRANCH" == "next" ]] && [[ "${TRAVIS_PULL_REQUEST}" = "false" ]]; then
       ./script/release.sh;
       ./script/deploy.sh;
     fi