misc - add mariadb 10.6 test server

Author: rusher

.travis.yml

@@ -43,11 +43,12 @@ jobs:
  - env: srv=mariadb v=10.2 local=1
  - env: srv=mariadb v=10.3 local=1
  - env: srv=mariadb v=10.4 local=1
+ - env: srv=mariadb v=10.6 local=1
  - env: srv=mariadb v=10.5 packet=40
  - env: srv=mariadb v=10.5 packet=8 jdk=openjdk8
  - env: srv=mariadb v=10.5 BENCH=1
  - env: srv=maxscale
- - env: srv=build v=10.6
+ - env: srv=mariadb v=10.6
  - env: srv=mysql v=5.7
  - env: srv=mysql v=8.0
  - env: srv=skysql