Travis Fix: bench reinstall pass MariaDB root user/pass as arguments (#16173)

* Added root password to .travis.yml

* Rearranged arguments
diff --git a/.travis.yml b/.travis.yml
index d77f9ef..f20128d 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -33,7 +33,7 @@
   - cd ~/frappe-bench
   - bench get-app erpnext $TRAVIS_BUILD_DIR
   - bench use test_site
-  - bench reinstall --yes
+  - bench reinstall --mariadb-root-username root --mariadb-root-password travis --yes
   - bench build
   - bench scheduler disable
   - sed -i 's/9000/9001/g' sites/common_site_config.json