缺少PHP 5.6.11 tokenizer

When running composer install I get the following error:

- phpunit/php-token-stream 1.4.8 requires ext-tokenizer * -> the requested PHP extension tokenizer is missing from your system.

I am using PHP 5.6.11.

If any extension is missing, it can be enabled by linking the appropriate ini file from /etc/php/mods-available.

The path varies from system to system and mostly depends on the version of the PHP used.

I was able to link the tokenizer extension by issuing this command

/etc/php/<Version-Number>/cli/conf.d$ sudo ln -s ../../mods-available/tokenizer.ini 20-tokenzer.ini