Build fails on Simpletests: General error: 2006 MySQL server has gone away

[kenorb]

Build: https://travis-ci.org/mycognitive/ads_features/builds/36707562

Log:

JavaScript 68 passes, 0 fails, 0 exceptions, and 1 debug message
PDOException: SQLSTATE[HY000]: General error: 2006 MySQL server has gone away: SELECT last_prefix FROM {simpletest_test_id} WHERE test_id = :test_id LIMIT 0, 1; Array
(
    [:test_id] => 1
)
 in dblog_watchdog() (line 160 of /var/www/ads/modules/dblog/dblog.module).
<h1>Uncaught exception thrown in shutdown function.</h1><p>PDOException: SQLSTATE[HY000]: General error: 2006 MySQL server has gone away: DELETE FROM {semaphore} 
WHERE  (value = :db_condition_placeholder_0) ; Array
(
    [:db_condition_placeholder_0] =&amp;gt; 1919012937542b11fbcc3392.02561649
)
 in lock_release_all() (line 269 of /var/www/ads/includes/lock.inc).</p><hr />PHP Fatal error:  Uncaught exception 'PDOException' with message 'SQLSTATE[HY000]: General error: 2006 MySQL server has gone away' in /var/www/ads/includes/database/database.inc:2171
Stack trace:
#0 /var/www/ads/includes/database/database.inc(2171): PDOStatement->execute(Array)
#1 /var/www/ads/includes/database/database.inc(683): DatabaseStatementBase->execute(Array, Array)
#2 /var/www/ads/includes/database/database.inc(2350): DatabaseConnection->query('SELECT expire, ...', Array, Array)
#3 /var/www/ads/includes/lock.inc(167): db_query('SELECT expire, ...', Array)
#4 /var/www/ads/includes/lock.inc(146): lock_may_be_available('schema:runtime:...')
#5 /var/www/ads/includes/bootstrap.inc(424): lock_acquire('schema:runtime:...')
#6 /var/www/ads/includes/bootstrap.inc(446): DrupalCacheArray->set(Array)
#7 [internal function]: DrupalCacheArray->__destruct()
#8 {main}
  thrown in /var/www/ads/includes/database/database.inc on line 2171
PHP Stack trace:
PHP   1. _drupal_exception_handler() /var/www/ads/includes/bootstrap.inc:0
PHP   2. _drupal_log_error() /var/www/ads/includes/bootstrap.inc:2338
Fatal error: Uncaught exception 'PDOException' with message 'SQLSTATE[HY000]: General error: 2006 MySQL server has gone away' in /var/www/ads/includes/database/database.inc on line 2171

[nseam]

Fixed