Run after_success scripts only once.

Author: RubenVerborgh

.travis.yml

@@ -4,6 +4,8 @@ node_js:
  - "8"
  - "10"
  - "node"
+env:
+ - DEFAULT_NODE_VERSION=10
 addons:
   apt:
     sources:
@@ -32,8 +34,12 @@ script:
   - npm run spec
   - npm run docs
 after_success:
-  - npm run coveralls
-  - ./.travis_build_pages
+  - if [ "$TRAVIS_NODE_VERSION" == "$DEFAULT_NODE_VERSION" ]; then
+      npm install coveralls;
+      node_modules/.bin/nyc --reporter=text-lcov mocha |
+        node_modules/.bin/coveralls;
+      ./.travis_build_pages;
+    fi
 cache:
   apt: true
   directories: