Build: Improve AppVeyor & Travis config

Author: sttk

.travis.yml

@@ -1,15 +1,19 @@
 sudo: false
 language: node_js
 node_js:
+  - "10"
   - "8"
   - "6"
   - "4"
   - "0.12"
   - "0.10"
-before_script:
-  - sed -i 's/4.0.0-alpha.1/4.0.0/g' node_modules/gulp/package.json
 after_script:
-  - npm run coveralls
-  - npm run lint
+  - if [ $(echo "${TRAVIS_NODE_VERSION}" | cut -d'.' -f1) -ge 6 ]; then
+      npm run coveralls;
+    fi
+
 git:
   depth: 10
+os:
+  - linux
+  - osx

appveyor.yml

@@ -9,6 +9,7 @@ environment:
     - nodejs_version: "4"
     - nodejs_version: "6"
     - nodejs_version: "8"
+    - nodejs_version: "10"
 
 install:
   - npm install -g npm@^3