Enable MySQL tests

.travis.yml

@@ -21,8 +21,8 @@ env:
 before_install:
   # create test database for mysql, mariadb and postgresql
   # mysql is currently disabled: https://github.com/OpenRefine/OpenRefine/issues/2043
-  #- mysql -u root -e 'CREATE DATABASE test_db;'
-  #- mysql -u root test_db < extensions/database/tests/conf/travis-mysql.sql
+  - mysql -u root -e 'CREATE DATABASE test_db;'
+  - mysql -u root test_db < extensions/database/tests/conf/travis-mysql.sql
   - psql -c 'CREATE DATABASE test_db;' -U postgres
   - psql -U postgres test_db < extensions/database/tests/conf/travis-pgsql.sql
   - cp extensions/database/tests/conf/travis_tests.xml extensions/database/tests/conf/tests.xml

extensions/database/tests/conf/travis_tests.xml

@@ -25,8 +25,6 @@
         <!-- See https://github.com/OpenRefine/OpenRefine/issues/2043 -->
         <groups>
             <run>
-                <exclude name="requiresMySQL"/>
-                <exclude name="requiresMariaDB" />
             </run>
         </groups> 
 		<classes>