.travis.yaml: Do not skip tagged builds

Author: darkowlzz

.travis.yml

@@ -14,8 +14,11 @@ env:
 before_install:
   - |
       if ! git diff --name-only $TRAVIS_COMMIT_RANGE | grep -qvE '(\.md)|(\.MD)|(\.png)|(\.pdf)|^(doc/)|^(MAINTAINERS)|^(LICENSE)'; then
+        # Do not skip if it's a tagged build.
+        if [[ -z "$TRAVIS_TAG" ]]; then
           echo "Only doc files were updated, not running the CI."
           exit
+        fi
       fi
   - sudo apt -y update && sudo apt install -y jq
   - go get github.com/golang/mock/gomock