taravis: disable embedded server tests
taravis: disable embedded server tests

Because it says the following:

    mysql-test-run: *** ERROR: Could not find any of /home/travis/build/mroonga/mroonga/libmysqld/examples/mysqltest_embedded /home/travis/build/mroonga/mroonga/client/mysqltest_embedded

naoa/mroonga,yoku0825/mroonga,naoa/mroonga,mroonga/mroonga,naoa/mroonga,mroonga/mroonga,mroonga/mroonga,yoku0825/mroonga,mroonga/mroonga,naoa/mroonga,naoa/mroonga,naoa/mroonga,yoku0825/mroonga,yoku0825/mroonga,yoku0825/mroonga,yoku0825/mroonga