Update and Convert the mysql example to mariadb

[bexelbie]

Conversion included:

• renaming directory
• adding docker provider
• using mariadb stock image instead of custom mysql image

Rename the mariadb example to note it is the Fedora example

[goern]

LGTM

[aweiteka]

Sounds like we're deprecating the mysql app. We probably won't remove it right away but put a note that mariadb should be used instead.

[vpavlin]

I added automated build for mariadb-fedora-atomicapp https://registry.hub.docker.com/u/projectatomic/mariadb-fedora-atomicapp/