Use different test domains for the v4 and v6 plugin handlers, to ensure that the v4 handler uses the v4 config and that the v6 handler uses the v6 config.
Signed-off-by: William Rory Kronmiller <wkronmiller@Williams-MacBook-Pro.local>
1.13.x=.13.x TRAVIS_OS_NAME=linux
1.14.x=.14.x TRAVIS_OS_NAME=linux
TRAVIS_OS_NAME=linux master=