v3.21.0-beta.7

Fixes

• Added general purpose error trap to Docker Desktop install script on Windows, maybe fixes #118
• Changed lando shellenv to print to stderr when it has no shellenv to print
• Fixed issue with wsl.exe throwing an error when not found #117
• Fixed issue with is-group-member throwing an when target group was nonexistent #116

Internal

• Improved is-group-member so it does not require the existence of the target group
• Improved run-command, run-elevated and run-powershell-script so they correctly handle pre-command executing errors eg ENOENT