Travis CI Memcache Service and Settings

[lcatlett]

Fixes #3077

Changes proposed:

Start the memcache service on Travis and add the memcached.so php extension to php.ini to allow for using memcache in Travis. Enable memcache for CI if the service is available.

Note: In looking over the travis config, it doesnt look like apc is installed or configured which may impact this work. I will open a separate issue if it looks like there is a bug.

Steps to test

1. Start travis build
2. Observe that memcache successfully started in the logs which should have output such as:

* memcached.service - memcached daemon
   Loaded: loaded (/lib/systemd/system/memcached.service; enabled; vendor preset: enabled)
   Active: active (running) since Fri 2018-09-07 18:42:58 UTC; 21h ago
 Main PID: 894 (memcached)
   CGroup: /system.slice/memcached.service
           `-894 /usr/bin/memcached -m 64 -p 11211 -u memcache -l 127.0.0.1 -c 1024

Sep 07 18:42:58 local systemd[1]: Started memcached daemon.

[ba66e77]

I see the sudo call to memcache in the build logs, but not the expected output.

The other thing I see is that even though they all passed, each of the builds contain

In Connection.php line 686:
                                                                               
  SQLSTATE[42S02]: Base table or view not found: 1146 Table 'drupal.key_value  
  ' doesn't exist: DELETE FROM {key_value}                                     
  WHERE (name IN (:db_condition_placeholder_0)) AND (collection = :db_conditi  
  on_placeholder_1); Array                                                     
  (                                                                            
      [:db_condition_placeholder_0] => drupal_css_cache_files                  
      [:db_condition_placeholder_1] => state                                   
  )                                                                            
                                                                               
In Statement.php line 59:
                                                                               
  SQLSTATE[42S02]: Base table or view not found: 1146 Table 'drupal.key_value  
  ' doesn't exist                                                              
                                                                               

[lcatlett]

@ba66e77 - for whatever reason the output of that service status command is different on my local Travis. On the live BLT builds it simply outputs:

0.02s$ sudo service memcached status
sudo service memcached status 
 * memcached is running

Looking for the above such as in https://travis-ci.org/acquia/blt/jobs/426141628#L595-L597 shows that memcache is running as expected now.

It looks like the SQLSTATE[42S02]: Base table or view not found: 1146 errors,` were not introduced by this PR and are occuring in every build including the latest release: https://travis-ci.org/acquia/blt/jobs/426199082#L1332-L1348

In looking through the full logs I noticed that the builds with the above error have a second issue with phpunit tests but it isnt flagged as an error (see https://travis-ci.org/acquia/blt/jobs/426199082#L956-L958);

Warning: include(../../scripts/phpunit/bootstrap.php): failed to open stream: No such file or directory in /home/travis/build/acquia/blt/tests/phpunit/bootstrap.php on line 8
Warning: include(): Failed opening '../../scripts/phpunit/bootstrap.php' for inclusion (include_path='.:/home/travis/.phpenv/versions/7.1.11/share/pear') in /home/travis/build/acquia/blt/tests/phpunit/bootstrap.php on line 8
PHP Warning:  include(../../scripts/phpunit/bootstrap.php): failed to open stream: No such file or directory in /home/travis/build/acquia/blt/tests/phpunit/bootstrap.php on line 8
PHP Warning:  include(): Failed opening '../../scripts/phpunit/bootstrap.php' for inclusion (include_path='.:/home/travis/.phpenv/versions/7.1.11/share/pear') in /home/travis/build/acquia/blt/tests/phpunit/bootstrap.php on line 8
Bootstrapping BLT testing framework...
To prevent recreation of sandbox master on each bootstrap, set BLT_RECREATE_SANDBOX_MASTER=0
Creating master sandbox in /tmp/blt-sandbox-master...
Loading composer repositories with package information

I don't know if these issues are somehow related but I will create bugs to investigate separately since they weren't introduced by the changes in this PR

[ba66e77]

Wow, you're right. I've traced those messages in the logs as far back as the 9.1.1 release. I've created #3084 to track investigating.