chore: set version to 2.1.6

Author: lucatume

slic.php

@@ -54,7 +54,7 @@
 ] );
 
 $cli_name = 'slic';
-const CLI_VERSION = '2.1.5';
+const CLI_VERSION = '2.1.6';
 
 // If the run-time option `-q`, for "quiet", is specified, then do not print the header.
 if ( in_array( '-q', $argv, true ) || ( in_array( 'exec', $argv, true ) && ! in_array( 'help', $argv, true ) ) ) {