Switched to working mirror for MariaDB 10.1

[khromov]

Noticed that I got MariaDB 5.5 on an install. When I investigated this it seems the layerjet.com server had gone down and I must have been served the default MariaDB version in trusty.

Changed the repo URL to one from a large swedish university - very unlikely to get shut down in the foreseeable future. After a fresh vagrant up I got 10.1 as expected.

[khromov]

Not quite sure why the build is failing (it was failing before this PR as well), but it almost looks like Travis has a pre-installed version of MariaDB 5.5 already?!

From the Travis error log:

install 'mariadb-server' 'python-mysqldb'' failed: mysql stop/waiting\ndpkg: mysql-client-5.5: dependency problems, but removing anyway as you requested:\n mysql-client depends on mysql-client-5.5.\n\nConfiguration file `/etc/mysql/my.cnf'\n ==> Modified (by you or by a script) since installation.\n ==> Package distributor has shipped an updated version.

[debo]

@khromov yes I had to make few changes in the mysql role too to make sure the environment is clean before installing the service via ansible. Please have a look here for the fix the PR so that I can merge it.

Thanks for your help and contribution.