MDL-55986 behat: Added option to optimize parallel runs by tags

run.php should only be used for running behat
before this patch if tags were passed, then behat.yml
was being re-written with features havings tags.
As this is not ideal, this option is now removed and
features with tags will be optimally split
by init.php when --optimize-run option is passed

admin/tool/behat/cli/util.php

@@ -57,6 +57,7 @@ list($options, $unrecognized) = cli_get_params(
         'fromrun'     => 1,
         'torun'       => 0,
         'run-with-theme' => false,
+        'optimize-runs' => '',
     ),
     array(
         'h' => 'help',
@@ -80,8 +81,9 @@ Options:
 --diag         Get behat test environment status code
 --updatesteps  Update feature step file.
 
--j, --parallel Number of parallel behat run operation
--m, --maxruns  Max parallel processes to be executed at one time.
+-j, --parallel   Number of parallel behat run operation
+-m, --maxruns    Max parallel processes to be executed at one time.
+--optimize-runs  Split features with specified tags in all parallel runs.
 --run-with-theme Run all core features with specified theme.
 
 -h, --help     Print out this help
@@ -185,7 +187,7 @@ if ($options['diag'] || $options['enable'] || $options['disable']) {
             $CFG->behatrunprocess = $i;
 
             // Update config file for each run.
-            behat_config_manager::update_config_file('', true, '', $options['run-with-theme'],
+            behat_config_manager::update_config_file('', true, $options['optimize-runs'], $options['run-with-theme'],
                 $options['parallel'], $i);
         }
         unset($CFG->behatrunprocess);
@@ -267,7 +269,7 @@ function commands_to_execute($options) {
         if ($options[$option]) {
             $extra .= " --$option";
             if ($value) {
-                $extra .= "=$value";
+                $extra .= "='$value'";
             }
         }
     }