Use full path for test in cloud::database::sql::mysql

At the moment it is not possible to use cloud::database::sql::mysql
on CentOS 7 because of the following error when trying to call the
binary 'test' in 'bootstrap-mysql'.

'test -d /var/lib/mysql/mysql' is not qualified and no path was
specified. Please qualify the command or specify a path.

Change-Id: I937ee32400da3f9c6154bc75ae8897e5c44dfab2

manifests/database/sql/mysql.pp

@@ -358,7 +358,7 @@ class cloud::database::sql::mysql (
       # but MariaDB is not packaged for Red Hat / CentOS 7 in MariaDB repository.
       exec { 'bootstrap-mysql':
         command => '/usr/bin/mysql_install_db --rpm --user=mysql',
-        unless  => 'test -d /var/lib/mysql/mysql',
+        unless  => '/usr/bin/test -d /var/lib/mysql/mysql',
         before  => Service['mysqld'],
         require => [Package[$mysql_server_package_name], File[$mysql_server_config_file]]
       }

spec/classes/cloud_database_sql_mysql_spec.rb

@@ -222,7 +222,7 @@ describe 'cloud::database::sql::mysql' do
       it 'configure mysql database' do
         is_expected.to contain_exec('bootstrap-mysql').with(
           :command => '/usr/bin/mysql_install_db --rpm --user=mysql',
-          :unless  => "test -d /var/lib/mysql/mysql",
+          :unless  => "/usr/bin/test -d /var/lib/mysql/mysql",
           :before  => 'Service[mysqld]'
         )
       end