Drush version no longer populated in env:info

[pwtyler]

% terminus help env:info
Description:
  Displays environment status and configuration.

Usage:
  env:info [options] [--] <site_env>
  env:info <site>.<env> Displays status and configuration for <site>'s <env> environment.

Arguments:
  site_env              Site & environment in the format `site-name.env`

Options:
      --format=FORMAT   Format the result data. Available formats: csv,json,list,null,php,print-r,string,table,tsv,var_dump,var_export,xml,yaml [default: "table"]
      --fields=FIELDS   Available fields: ID (id), Created (created), Domain (domain), Locked (locked), Initialized (initialized), Connection Mode (connection_mode), PHP Version (php_version), Drush Version (drush_version) [default: ""]
      --field=FIELD     Select just one field, and force format to *string*. [default: ""]
  -h, --help            Display help for the given command. When no command is given display help for the list command
  -q, --quiet           Do not output any message
  -V, --version         Display this application version
      --ansi|--no-ansi  Force (or disable --no-ansi) ANSI output
  -n, --no-interaction  Do not ask any interactive question
  -D, --define=DEFINE   Define a configuration item value. (multiple values allowed)
  -y, --yes             Answer all confirmations with "yes"
  -v|vv|vvv, --verbose  Increase the verbosity of messages: 1 for normal output (-v), 2 for more verbose output (-vv), and 3 for debug (-vvv)
% terminus env:info --fields=drush_version -- 05ad39a3-233b-4c28-b1fc-0c672fe11f4d.dev
% echo $?
0
% terminus env:info --fields=drush_version 05ad39a3-233b-4c28-b1fc-0c672fe11f4d.dev
% echo $?
0

Drush version is no longer populated, remove it from available options in fields and related code, or update to use a more correct value.