Skip Travis build if only docs/website have changed

.travis.yml

@@ -15,6 +15,14 @@ go:
 sudo: required
 
 before_install:
+  - |
+    if [ "$TRAVIS_PULL_REQUEST" != "false" ]; then
+      TRAVIS_COMMIT_RANGE="FETCH_HEAD...$TRAVIS_BRANCH"
+    fi
+    git diff --name-only $TRAVIS_COMMIT_RANGE | grep -qvE '(\.md$)|(^(docs|website))/' || {
+      echo "Only docs were updated, stopping build process."
+      exit
+    }
   - make go-dependencies
 
 jobs: