Rename profile "travis" to "mysql"

The puzzle `1154-b99af137` from #1154 has to be resolved:

https://github.com/php-coder/mystamps/blob/adfb6ef571b9dfc9bd3adafb0b4156a0af7f5073/src/main/resources/application-travis.properties#L2-L2

Tech debt for: adfb6ef571b9dfc9bd3adafb0b4156a0af7f5073 (#1154)