Attempt to generate the danish locale.

Refs #10873

.travis.yml

@@ -66,6 +66,7 @@ before_install:
   - if [[ $TRAVIS_PHP_VERSION = 5.6 ]] ; then echo yes | pecl install apcu-4.0.10; fi
   - if [[ $TRAVIS_PHP_VERSION = 7.0 ]] ; then echo yes | pecl install channel://pecl.php.net/apcu-5.1.5; fi
   - if [[ $TRAVIS_PHP_VERSION = 5.6 && $DB = 'mysql' ]] ; then wget http://xcache.lighttpd.net/pub/Releases/3.2.0/xcache-3.2.0.tar.gz; tar xf xcache-3.2.0.tar.gz; pushd xcache-3.2.0; phpize; ./configure; make; NO_INTERACTION=1 make test; make install; popd;printf "extension=xcache.so\nxcache.size=64M\nxcache.var_size=16M\nxcache.test=On" > ~/.phpenv/versions/$(phpenv version-name)/etc/php.ini; fi
+  - sudo locale-gen da_DK
 
 before_script:
   - composer install --prefer-dist --no-interaction