- copies behaviour from bash installer

Signed-off-by: John McCabe <john@johnmccabe.net>

Signed-off-by: John McCabe <john@johnmccabe.net>

- Generates the password to mirror deploy_stack.sh
- Uses hardcoded admin to mirror deploy_stack.sh
- Uses throw to exit when error
- Updates faas-cli login command for Powershell

Signed-off-by: John McCabe <john@johnmccabe.net>

This commit updates deploy_stack.ps1 to check that Docker is running in
Swarm mode before proceeding.

Signed-off-by: John McCabe <john@johnmccabe.net>

This commit updates the Windows deploy_stack.ps1 to set the
basic-auth-user and basic-auth-password secrets if absent.

Signed-off-by: John McCabe <john@johnmccabe.net>

This commit adds a PowerShell script that mirrors the existing `deploy_stack.*` scripts.

It also checks that docker is installed and returns a readable error if not found (the alternative is a rather cryptic PowerShell error).

The docker stack command itself returns a readable error if no swarm has been initialised.

Signed-off-by: John McCabe <john@johnmccabe.net>