Update required dist to :trusty (#5906)

Travis is phasing out support for Ubuntu precise environments.

[ci skip]

.travis.yml

@@ -32,7 +32,7 @@ rvm:
   - 2.4.1
 
 sudo: false
-dist: precise
+dist: trusty
 
 cache:
   bundler: true

script/ci_setup.sh

@@ -42,7 +42,8 @@ run() {
 }
 
 if [ $2 = "mysql" ]; then
-  run "mysql -e 'create database travis_ci_test;'"
+  run "mysql -u root -e \"CREATE DATABASE IF NOT EXISTS travis_ci_test DEFAULT CHARACTER SET = 'utf8' DEFAULT COLLATE 'utf8_general_ci';\""
+  run "mysql -u root -e \"GRANT ALL ON travis_ci_test.* TO 'travis'@'localhost';\""
   run "cp script/templates/database.travis.mysql.yml config/database.yml"
 
 elif [ $2 = "postgres" ]; then