Fix demo installation

[aaa2000]

Q	A
Bug fix?	yes
New feature?	no
BC breaks?	no
Deprecations?	no
Tests pass?	yes
Fixed tickets	#30
License	MIT

[aaa2000]

I noticed that the Pull Request #24 has removed the command bin/console assets:install https://github.com/api-platform/demo/pull/24/files#diff-507acfb69e262d39c47cc1a687c1aab4L12 and symbolic links prevent assets loading.

The flex recipe remove now "--relative" and "--symlink" options by default See symfony/recipes#406

[dunglas]

Thanks for fixing the demo @aaa2000!

[aaa2000]

Wow you are fast, I have a doubt about until bin/console doctrine:query:sql "SELECT 1" --quiet; do, now I try with until pg_isready --timeout=0 --dbname="${DATABASE_URL}"; do and it works. (I have removed containers and api-platform-demo_db-data volume before retry)

The command can pollute the output

php_1          |  [OK]
php_1          | Waiting for Postgres to be ready...
php_1          | 2018-09-17T20:51:41+00:00 [error] Error thrown while running command "doctrine:query:sql 'SELECT 1' --quiet". Message: "An exception occurred in driver: SQLSTATE[08006] [7] FATAL:  the database system is starting up"
php_1          | 
php_1          | In AbstractPostgreSQLDriver.php line 93:
php_1          |                                                                                
php_1          |   An exception occurred in driver: SQLSTATE[08006] [7] FATAL:  the database s  
php_1          |   ystem is starting up                                                         
php_1          |                                                                                
php_1          | 
php_1          | In PDOConnection.php line 50:
php_1          |                                                                   
php_1          |   SQLSTATE[08006] [7] FATAL:  the database system is starting up  
php_1          |                                                                   
php_1          | 
php_1          | In PDOConnection.php line 46:
php_1          |                                                                   
php_1          |   SQLSTATE[08006] [7] FATAL:  the database system is starting up  
php_1          |                                                                   
php_1          | 
php_1          | doctrine:query:sql [--depth DEPTH] [--force-fetch] [--connection [CONNECTION]] [-h|--help] [-q|--quiet] [-v|vv|vvv|--verbose] [-V|--version] [--ansi] [--no-ansi] [-n|--no-interaction] [-e|--env ENV] [--no-debug] [--] <command> <sql>
php_1          | 
php_1          | 
php_1          |  Updating database schema...
php_1          | 
php_1          |      8 queries were executed
php_1          | 
php_1          |  [OK] Database schema updated successfully!                                     
php_1          |