ci: update html5validator to 0.3.3

This also updates vnu.jar from 18.3.0 to 18.11.5

Changelogs:
- https://github.com/svenkreiss/html5validator/releases/tag/v0.3.2
- https://github.com/svenkreiss/html5validator/releases/tag/v0.3.3
- https://github.com/validator/validator/blob/ab7acd24f9e28cecfd0434c20d9a8148af91150f/CHANGELOG.md#18115

Fix #1169

Author: php-coder

.travis.yml

@@ -21,7 +21,7 @@ before_script:
       mkdir -p /tmp/uploads /tmp/preview;
       cp src/main/resources/test/test.png /tmp/uploads/1.png;
       npm install -g bootlint;
-      pip install --user html5validator==0.3.1 robotframework-lint==1.1 ansible==2.9.2 ansible-lint;
+      pip install --user html5validator==0.3.3 robotframework-lint==1.1 ansible==2.9.2 ansible-lint;
       if [ "$TRAVIS_PULL_REQUEST" != 'false' ]; then
         gem install danger nokogiri --no-document;
       fi;