Custom exec commands are executed in the current directory

[eysi09]

Bug

Current Behavior

I have a custom command that runs a local script, something like:

# In <project-root>/custom-commands.garden.yml
kind: Command
name: my-command
exec:
  command: [./scripts/my-script.sh]

If I run it in from the project root the command works as expected.

If I run it from a child dir, I get:

Command exited with code undefined

I'm assuming we're not exec-ing the script from the location of the custom-commands.garden.yml file.

Also, I would expect a better error.

I'm on latest master.

[vvagaytsev]

@eysi09 should we always consider the project root as a cwd when we run the commands?

[vvagaytsev]

Closing as a duplicate of #3151.